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Provided is a buggy for loop that tries to accumulate some values out of some dictionaries. Insert a try/except so that the code passes. |
di = [{"Puppies": 17, 'Kittens': 9, "Birds": 23, 'Fish': 90, "Hamsters": 49}, {"Puppies": 23, "Birds": 29, "Fish": 20, "Mice": 20, "Snakes": 7}, {"Fish": 203, "Hamsters": 93, "Snakes": 25, "Kittens": 89}, {"Birds": 20, "Puppies": 90, "Snakes": 21, "Fish": 10, "Kittens": 67}]
total = 0
for diction in di:
try:
diction.keys == "Puppies"
total = total + diction['Puppies']
except:
pass
print("Total number of puppies:", total)
| _____no_output_____ | MIT | Class ,Constractor,Inheritance,overriding,Exception.ipynb | Ks226/upgard_code |
The code below takes the list of country, country, and searches to see if it is in the dictionary gold which shows some countries who won gold during the Olympics. However, this code currently does not work. Correctly add try/except clause in the code so that it will correctly populate the list, country_gold, with either the number of golds won or the string “Did not get gold”. |
gold = {"US":46, "Fiji":1, "Great Britain":27, "Cuba":5, "Thailand":2, "China":26, "France":10}
country = ["Fiji", "Chile", "Mexico", "France", "Norway", "US"]
country_gold = []
print(gold.keys())
for x in country:
try:
x in gold.keys()
country_gold.append(gold[x])
except KeyError:
country_gold.append("Did not get gold")
print(country_gold) | _____no_output_____ | MIT | Class ,Constractor,Inheritance,overriding,Exception.ipynb | Ks226/upgard_code |
The list, numb, contains integers. Write code that populates the list remainder with the remainder of 36 divided by each number in numb. For example, the first element should be 0, because 36/6 has no remainder. If there is an error, have the string “Error” appear in the remainder. |
numb = [6, 0, 36, 8, 2, 36, 0, 12, 60, 0, 45, 0, 3, 23]
remainder = []
for i in numb:
if (i == 0):
remainder.append("Error")
elif (36 % i):
remainder.append(36 % i)
elif (36 % i == 0):
remainder.append(0)
print(remainder)
| _____no_output_____ | MIT | Class ,Constractor,Inheritance,overriding,Exception.ipynb | Ks226/upgard_code |
Provided is buggy code, insert a try/except so that the code passes. |
lst = [2,4,10,42,12,0,4,7,21,4,83,8,5,6,8,234,5,6,523,42,34,0,234,1,435,465,56,7,3,43,23]
lst_three = []
for num in lst:
try:
if 3 % num == 0:
lst_three.append(num)
except ZeroDivisionError:
pass
print(lst_three)
| _____no_output_____ | MIT | Class ,Constractor,Inheritance,overriding,Exception.ipynb | Ks226/upgard_code |
Write code so that the buggy code provided works using a try/except. When the codes does not work in the try, have it append to the list attempt the string “Error”. |
full_lst = ["ab", 'cde', 'fgh', 'i', 'jkml', 'nop', 'qr', 's', 'tv', 'wxy', 'z']
attempt = []
for elem in full_lst:
try:
attempt.append(elem[1])
except:
attempt.append("Error")
| _____no_output_____ | MIT | Class ,Constractor,Inheritance,overriding,Exception.ipynb | Ks226/upgard_code |
The following code tries to append the third element of each list in conts to the new list third_countries. Currently, the code does not work. Add a try/except clause so the code runs without errors, and the string ‘Continent does not have 3 countries’ is appended to countries instead of producing an error. |
conts = [['Spain', 'France', 'Greece', 'Portugal', 'Romania', 'Germany'], ['USA', 'Mexico', 'Canada'], ['Japan', 'China', 'Korea', 'Vietnam', 'Cambodia'], ['Argentina', 'Chile', 'Brazil', 'Ecuador', 'Uruguay', 'Venezuela'], ['Australia'], ['Zimbabwe', 'Morocco', 'Kenya', 'Ethiopa', 'South Africa'], ['Antarctica']]
third_countries = []
for c in conts:
try:
third_countries.append(c[2])
except IndexError:
third_countries.append("Continent does not have 3 countries")
| _____no_output_____ | MIT | Class ,Constractor,Inheritance,overriding,Exception.ipynb | Ks226/upgard_code |
The buggy code below prints out the value of the sport in the list sport. Use try/except so that the code will run properly. If the sport is not in the dictionary, ppl_play, add it in with the value of 1. |
sport = ["hockey", "basketball", "soccer", "tennis", "football", "baseball"]
ppl_play = {"hockey":4, "soccer": 10, "football": 15, "tennis": 8}
for x in sport:
try:
print(ppl_play[x])
except KeyError:
ppl_play[x] = 1 | _____no_output_____ | MIT | Class ,Constractor,Inheritance,overriding,Exception.ipynb | Ks226/upgard_code |
Provided is a buggy for loop that tries to accumulate some values out of some dictionaries. Insert a try/except so that the code passes. If the key is not there, initialize it in the dictionary and set the value to zero. |
di = [{"Puppies": 17, 'Kittens': 9, "Birds": 23, 'Fish': 90, "Hamsters": 49}, {"Puppies": 23, "Birds": 29, "Fish": 20, "Mice": 20, "Snakes": 7}, {"Fish": 203, "Hamsters": 93, "Snakes": 25, "Kittens": 89}, {"Birds": 20, "Puppies": 90, "Snakes": 21, "Fish": 10, "Kittens": 67}]
total = 0
for diction in di:
try:
diction.keys() == "Puppies"
total = total + diction['Puppies']
except :
pass
if("Puppies" not in diction.keys()):
diction["Puppies"] = 0
print("Total number of puppies:", total)
VOWEL_COST = 250
LETTERS = 'ABCDEFGHIJKLMNOPQRSTUVWXYZ'
VOWELS = 'AEIOU'
# Write the WOFPlayer class definition (part A) here
class WOFPlayer:
prizeMoney = 0
prizes = []
def __init__(self, name):
self.name = name
def addMoney(self, amt):
self.prizeMoney += amt
def goBankrupt(self):
self.prizeMoney = 0
def addPrize(prizes,prize):
prizes.append(prize)
def __str__(self):
return "%s (%s)" % (self.name, self.prize)
# Write the WOFHumanPlayer class definition (part B) here
class WOFHumanPlayer(WOFPlayer):
def getMove(self, category, obscuredPhrase, guesse):
input(
"{%s} has ${%s}\n"
"Category: {%s}\n"
"Phrase: {%s}\n"
"Guessed: {%s}\n"
"Guess a letter, phrase, or type 'exit' or 'pass':\n") % (
self.name, self.prizeMoney, category, obscuredPhrase, guesse)
return ("%s") % (guesse)
# Write the WOFComputerPlayer class definition (part C) here
class WOFComputerPlayer(WOFPlayer):
SORTED_FREQUENCIES = "ZQXJKVBPYGFWMUCLDRHSNIOATE"
VOWEL_COST = 250
VOWELS = "AEIOU"
def __init__(self, difficulty):
self.difficulty = difficulty
def smartCoinFlip(self):
random_num = random.randint(1, 10)
if random_num > self.difficulty:
return True
else:
return False
def getPossibleLetters(self, guessed):
return guessed.upper()
def getMove(category, obscuredPhrase, guessed):
return getPossibleLetters(guessed) | _____no_output_____ | MIT | Class ,Constractor,Inheritance,overriding,Exception.ipynb | Ks226/upgard_code |
Disaggregation | from __future__ import print_function, division
import time
from matplotlib import rcParams
import matplotlib.pyplot as plt
import pandas as pd
import numpy as np
from six import iteritems
from nilmtk import DataSet, TimeFrame, MeterGroup, HDFDataStore
from nilmtk.disaggregate import CombinatorialOptimisation, FHMM
import nilmtk.utils
%matplotlib inline
rcParams['figure.figsize'] = (13, 6) | _____no_output_____ | Apache-2.0 | docs/manual/user_guide/disaggregation_and_metrics.ipynb | Ming-er/nilmtk |
Dividing data into train and test set | train = DataSet('/data/redd.h5')
test = DataSet('/data/redd.h5') | _____no_output_____ | Apache-2.0 | docs/manual/user_guide/disaggregation_and_metrics.ipynb | Ming-er/nilmtk |
Let us use building 1 for demo purposes | building = 1 | _____no_output_____ | Apache-2.0 | docs/manual/user_guide/disaggregation_and_metrics.ipynb | Ming-er/nilmtk |
Let's split data at April 30th | train.set_window(end="2011-04-30")
test.set_window(start="2011-04-30")
train_elec = train.buildings[1].elec
test_elec = test.buildings[1].elec | _____no_output_____ | Apache-2.0 | docs/manual/user_guide/disaggregation_and_metrics.ipynb | Ming-er/nilmtk |
Visualizing the data | train_elec.plot()
test_elec.mains().plot() | _____no_output_____ | Apache-2.0 | docs/manual/user_guide/disaggregation_and_metrics.ipynb | Ming-er/nilmtk |
REDD data set has got appliance level data sampled every 3 or 4 seconds and mains data sampled every 1 second. Let us verify the same. | fridge_meter = train_elec['fridge']
fridge_df = next(fridge_meter.load())
fridge_df.head()
mains = train_elec.mains()
mains_df = next(mains.load())
mains_df.head() | _____no_output_____ | Apache-2.0 | docs/manual/user_guide/disaggregation_and_metrics.ipynb | Ming-er/nilmtk |
Since, both of these are sampled at different frequencies, we will downsample both to 1 minute resolution. We will also select the top-5 appliances in terms of energy consumption and use them for training our FHMM and CO models. Selecting top-5 appliances | top_5_train_elec = train_elec.submeters().select_top_k(k=5)
top_5_train_elec | _____no_output_____ | Apache-2.0 | docs/manual/user_guide/disaggregation_and_metrics.ipynb | Ming-er/nilmtk |
Training and disaggregation A function to disaggregate the mains data to constituent appliances and return the predictions | def predict(clf, test_elec, sample_period, timezone):
pred = {}
gt= {}
# "ac_type" varies according to the dataset used.
# Make sure to use the correct ac_type before using the default parameters in this code.
for i, chunk in enumerate(test_elec.mains().load(physical_quantity = 'power', ac_type = 'apparent', sample_period=sample_period)):
chunk_drop_na = chunk.dropna()
pred[i] = clf.disaggregate_chunk(chunk_drop_na)
gt[i]={}
for meter in test_elec.submeters().meters:
# Only use the meters that we trained on (this saves time!)
gt[i][meter] = next(meter.load(physical_quantity = 'power', ac_type = 'active', sample_period=sample_period))
gt[i] = pd.DataFrame({k:v.squeeze() for k,v in iteritems(gt[i]) if len(v)}, index=next(iter(gt[i].values())).index).dropna()
# If everything can fit in memory
gt_overall = pd.concat(gt)
gt_overall.index = gt_overall.index.droplevel()
pred_overall = pd.concat(pred)
pred_overall.index = pred_overall.index.droplevel()
# Having the same order of columns
gt_overall = gt_overall[pred_overall.columns]
#Intersection of index
gt_index_utc = gt_overall.index.tz_convert("UTC")
pred_index_utc = pred_overall.index.tz_convert("UTC")
common_index_utc = gt_index_utc.intersection(pred_index_utc)
common_index_local = common_index_utc.tz_convert(timezone)
gt_overall = gt_overall.loc[common_index_local]
pred_overall = pred_overall.loc[common_index_local]
appliance_labels = [m for m in gt_overall.columns.values]
gt_overall.columns = appliance_labels
pred_overall.columns = appliance_labels
return gt_overall, pred_overall | _____no_output_____ | Apache-2.0 | docs/manual/user_guide/disaggregation_and_metrics.ipynb | Ming-er/nilmtk |
Train using 2 benchmarking algorithms - Combinatorial Optimisation (CO) and Factorial Hidden Markov Model (FHMM) | classifiers = {'CO':CombinatorialOptimisation(), 'FHMM':FHMM()}
predictions = {}
sample_period = 120
for clf_name, clf in classifiers.items():
print("*"*20)
print(clf_name)
print("*" *20)
start = time.time()
# Note that we have given the sample period to downsample the data to 1 minute.
# If instead of top_5 we wanted to train on all appliance, we would write
# fhmm.train(train_elec, sample_period=60)
clf.train(top_5_train_elec, sample_period=sample_period)
end = time.time()
print("Runtime =", end-start, "seconds.")
gt, predictions[clf_name] = predict(clf, test_elec, sample_period, train.metadata['timezone'])
| ********************
CO
********************
Training model for submeter 'ElecMeter(instance=11, building=1, dataset='REDD', appliances=[Appliance(type='microwave', instance=1)])'
Training model for submeter 'ElecMeter(instance=8, building=1, dataset='REDD', appliances=[Appliance(type='sockets', instance=2)])'
Training model for submeter 'ElecMeter(instance=9, building=1, dataset='REDD', appliances=[Appliance(type='light', instance=1)])'
Training model for submeter 'ElecMeter(instance=5, building=1, dataset='REDD', appliances=[Appliance(type='fridge', instance=1)])'
Training model for submeter 'ElecMeter(instance=6, building=1, dataset='REDD', appliances=[Appliance(type='dish washer', instance=1)])'
Done training!
Runtime = 1.8285462856292725 seconds.
Loading data for meter ElecMeterID(instance=2, building=1, dataset='REDD')
Done loading data all meters for this chunk.
Estimating power demand for 'ElecMeter(instance=11, building=1, dataset='REDD', appliances=[Appliance(type='microwave', instance=1)])'
Estimating power demand for 'ElecMeter(instance=8, building=1, dataset='REDD', appliances=[Appliance(type='sockets', instance=2)])'
Estimating power demand for 'ElecMeter(instance=9, building=1, dataset='REDD', appliances=[Appliance(type='light', instance=1)])'
Estimating power demand for 'ElecMeter(instance=5, building=1, dataset='REDD', appliances=[Appliance(type='fridge', instance=1)])'
Estimating power demand for 'ElecMeter(instance=6, building=1, dataset='REDD', appliances=[Appliance(type='dish washer', instance=1)])'
Loading data for meter ElecMeterID(instance=4, building=1, dataset='REDD')
Done loading data all meters for this chunk.
Loading data for meter ElecMeterID(instance=20, building=1, dataset='REDD')
Done loading data all meters for this chunk.
********************
FHMM
********************
Training model for submeter 'ElecMeter(instance=11, building=1, dataset='REDD', appliances=[Appliance(type='microwave', instance=1)])'
Training model for submeter 'ElecMeter(instance=8, building=1, dataset='REDD', appliances=[Appliance(type='sockets', instance=2)])'
Training model for submeter 'ElecMeter(instance=9, building=1, dataset='REDD', appliances=[Appliance(type='light', instance=1)])'
Training model for submeter 'ElecMeter(instance=5, building=1, dataset='REDD', appliances=[Appliance(type='fridge', instance=1)])'
Training model for submeter 'ElecMeter(instance=6, building=1, dataset='REDD', appliances=[Appliance(type='dish washer', instance=1)])'
Runtime = 2.4450082778930664 seconds.
Loading data for meter ElecMeterID(instance=2, building=1, dataset='REDD')
Done loading data all meters for this chunk.
Loading data for meter ElecMeterID(instance=4, building=1, dataset='REDD')
Done loading data all meters for this chunk.
Loading data for meter ElecMeterID(instance=20, building=1, dataset='REDD')
Done loading data all meters for this chunk.
| Apache-2.0 | docs/manual/user_guide/disaggregation_and_metrics.ipynb | Ming-er/nilmtk |
Using prettier labels! | appliance_labels = [m.label() for m in gt.columns.values]
gt.columns = appliance_labels
predictions['CO'].columns = appliance_labels
predictions['FHMM'].columns = appliance_labels | _____no_output_____ | Apache-2.0 | docs/manual/user_guide/disaggregation_and_metrics.ipynb | Ming-er/nilmtk |
Taking a look at the ground truth of top 5 appliance power consumption | gt.head()
predictions['CO'].head()
predictions['FHMM'].head() | _____no_output_____ | Apache-2.0 | docs/manual/user_guide/disaggregation_and_metrics.ipynb | Ming-er/nilmtk |
Plotting the predictions against the actual usage | predictions['CO']['Fridge'].head(300).plot(label="Pred")
gt['Fridge'].head(300).plot(label="GT")
plt.legend()
predictions['FHMM']['Fridge'].head(300).plot(label="Pred")
gt['Fridge'].head(300).plot(label="GT")
plt.legend() | _____no_output_____ | Apache-2.0 | docs/manual/user_guide/disaggregation_and_metrics.ipynb | Ming-er/nilmtk |
Comparing NILM algorithms (CO vs FHMM) `nilmtk.utils.compute_rmse` is an extended of the following, handling both missing values and labels better:```pythondef compute_rmse(gt, pred): from sklearn.metrics import mean_squared_error rms_error = {} for appliance in gt.columns: rms_error[appliance] = np.sqrt(mean_squared_error(gt[appliance], pred[appliance])) return pd.Series(rms_error)``` | ? nilmtk.utils.compute_rmse
rmse = {}
for clf_name in classifiers.keys():
rmse[clf_name] = nilmtk.utils.compute_rmse(gt, predictions[clf_name])
rmse = pd.DataFrame(rmse)
rmse | _____no_output_____ | Apache-2.0 | docs/manual/user_guide/disaggregation_and_metrics.ipynb | Ming-er/nilmtk |
Write and Save Files in PythonEstimated time needed: **25** minutes ObjectivesAfter completing this lab you will be able to:* Write to files using Python libraries Table of Contents Writing Files Appending Files Additional File modes Copy a File Writing Files We can open a file object using the method write() to save the text file to a list. To write to a file, the mode argument must be set to **w**. Let’s write a file **Example2.txt** with the line: **“This is line A”** | # Write line to file
exmp2 = '/resources/data/Example2.txt'
with open(exmp2, 'w') as writefile:
writefile.write("This is line A") | _____no_output_____ | MIT | Python for Data Science, AI & Development/4. Working with Data in Python/Writing Files with Open.ipynb | aqafridi/Data-Analytics |
We can read the file to see if it worked: | # Read file
with open(exmp2, 'r') as testwritefile:
print(testwritefile.read()) | _____no_output_____ | MIT | Python for Data Science, AI & Development/4. Working with Data in Python/Writing Files with Open.ipynb | aqafridi/Data-Analytics |
We can write multiple lines: | # Write lines to file
with open(exmp2, 'w') as writefile:
writefile.write("This is line A\n")
writefile.write("This is line B\n") | _____no_output_____ | MIT | Python for Data Science, AI & Development/4. Working with Data in Python/Writing Files with Open.ipynb | aqafridi/Data-Analytics |
The method .write() works similar to the method .readline(), except instead of reading a new line it writes a new line. The process is illustrated in the figure. The different colour coding of the grid represents a new line added to the file after each method call. You can check the file to see if your results are correct | # Check whether write to file
with open(exmp2, 'r') as testwritefile:
print(testwritefile.read()) | _____no_output_____ | MIT | Python for Data Science, AI & Development/4. Working with Data in Python/Writing Files with Open.ipynb | aqafridi/Data-Analytics |
We write a list to a **.txt** file as follows: | # Sample list of text
Lines = ["This is line A\n", "This is line B\n", "This is line C\n"]
Lines
# Write the strings in the list to text file
with open('Example2.txt', 'w') as writefile:
for line in Lines:
print(line)
writefile.write(line) | _____no_output_____ | MIT | Python for Data Science, AI & Development/4. Working with Data in Python/Writing Files with Open.ipynb | aqafridi/Data-Analytics |
We can verify the file is written by reading it and printing out the values: | # Verify if writing to file is successfully executed
with open('Example2.txt', 'r') as testwritefile:
print(testwritefile.read()) | _____no_output_____ | MIT | Python for Data Science, AI & Development/4. Working with Data in Python/Writing Files with Open.ipynb | aqafridi/Data-Analytics |
However, note that setting the mode to **w** overwrites all the existing data in the file. | with open('Example2.txt', 'w') as writefile:
writefile.write("Overwrite\n")
with open('Example2.txt', 'r') as testwritefile:
print(testwritefile.read()) | _____no_output_____ | MIT | Python for Data Science, AI & Development/4. Working with Data in Python/Writing Files with Open.ipynb | aqafridi/Data-Analytics |
Appending Files We can write to files without losing any of the existing data as follows by setting the mode argument to append: **a**. you can append a new line as follows: | # Write a new line to text file
with open('Example2.txt', 'a') as testwritefile:
testwritefile.write("This is line C\n")
testwritefile.write("This is line D\n")
testwritefile.write("This is line E\n") | _____no_output_____ | MIT | Python for Data Science, AI & Development/4. Working with Data in Python/Writing Files with Open.ipynb | aqafridi/Data-Analytics |
You can verify the file has changed by running the following cell: | # Verify if the new line is in the text file
with open('Example2.txt', 'r') as testwritefile:
print(testwritefile.read()) | _____no_output_____ | MIT | Python for Data Science, AI & Development/4. Working with Data in Python/Writing Files with Open.ipynb | aqafridi/Data-Analytics |
Additional modes It's fairly ineffecient to open the file in **a** or **w** and then reopening it in **r** to read any lines. Luckily we can access the file in the following modes:* **r+** : Reading and writing. Cannot truncate the file.* **w+** : Writing and reading. Truncates the file.* **a+** : Appending and Reading. Creates a new file, if none exists. You dont have to dwell on the specifics of each mode for this lab. Let's try out the **a+** mode: | with open('Example2.txt', 'a+') as testwritefile:
testwritefile.write("This is line E\n")
print(testwritefile.read()) | _____no_output_____ | MIT | Python for Data Science, AI & Development/4. Working with Data in Python/Writing Files with Open.ipynb | aqafridi/Data-Analytics |
There were no errors but read() also did not output anything. This is because of our location in the file. Most of the file methods we've looked at work in a certain location in the file. .write() writes at a certain location in the file. .read() reads at a certain location in the file and so on. You can think of this as moving your pointer around in the notepad to make changes at specific location. Opening the file in **w** is akin to opening the .txt file, moving your cursor to the beginning of the text file, writing new text and deleting everything that follows.Whereas opening the file in **a** is similiar to opening the .txt file, moving your cursor to the very end and then adding the new pieces of text. It is often very useful to know where the 'cursor' is in a file and be able to control it. The following methods allow us to do precisely this -* .tell() - returns the current position in bytes* .seek(offset,from) - changes the position by 'offset' bytes with respect to 'from'. From can take the value of 0,1,2 corresponding to beginning, relative to current position and end Now lets revisit **a+** | with open('Example2.txt', 'a+') as testwritefile:
print("Initial Location: {}".format(testwritefile.tell()))
data = testwritefile.read()
if (not data): #empty strings return false in python
print('Read nothing')
else:
print(testwritefile.read())
testwritefile.seek(0,0) # move 0 bytes from beginning.
print("\nNew Location : {}".format(testwritefile.tell()))
data = testwritefile.read()
if (not data):
print('Read nothing')
else:
print(data)
print("Location after read: {}".format(testwritefile.tell()) ) | _____no_output_____ | MIT | Python for Data Science, AI & Development/4. Working with Data in Python/Writing Files with Open.ipynb | aqafridi/Data-Analytics |
Finally, a note on the difference between **w+** and **r+**. Both of these modes allow access to read and write methods, however, opening a file in **w+** overwrites it and deletes all pre-existing data. To work with a file on existing data, use **r+** and **a+**. While using **r+**, it can be useful to add a .truncate() method at the end of your data. This will reduce the file to your data and delete everything that follows. In the following code block, Run the code as it is first and then run it with the .truncate(). | with open('Example2.txt', 'r+') as testwritefile:
data = testwritefile.readlines()
testwritefile.seek(0,0) #write at beginning of file
testwritefile.write("Line 1" + "\n")
testwritefile.write("Line 2" + "\n")
testwritefile.write("Line 3" + "\n")
testwritefile.write("finished\n")
#Uncomment the line below
#testwritefile.truncate()
testwritefile.seek(0,0)
print(testwritefile.read())
| _____no_output_____ | MIT | Python for Data Science, AI & Development/4. Working with Data in Python/Writing Files with Open.ipynb | aqafridi/Data-Analytics |
Copy a File Let's copy the file **Example2.txt** to the file **Example3.txt**: | # Copy file to another
with open('Example2.txt','r') as readfile:
with open('Example3.txt','w') as writefile:
for line in readfile:
writefile.write(line) | _____no_output_____ | MIT | Python for Data Science, AI & Development/4. Working with Data in Python/Writing Files with Open.ipynb | aqafridi/Data-Analytics |
We can read the file to see if everything works: | # Verify if the copy is successfully executed
with open('Example3.txt','r') as testwritefile:
print(testwritefile.read()) | _____no_output_____ | MIT | Python for Data Science, AI & Development/4. Working with Data in Python/Writing Files with Open.ipynb | aqafridi/Data-Analytics |
After reading files, we can also write data into files and save them in different file formats like **.txt, .csv, .xls (for excel files) etc**. You will come across these in further examples Now go to the directory to ensure the **.txt** file exists and contains the summary data that we wrote. Exercise Your local university's Raptors fan club maintains a register of its active members on a .txt document. Every month they update the file by removing the members who are not active. You have been tasked with automating this with your Python skills. Given the file currentMem, Remove each member with a 'no' in their Active coloumn. Keep track of each of the removed members and append them to the exMem file. Make sure the format of the original files in preserved. (*Hint: Do this by reading/writing whole lines and ensuring the header remains* ) Run the code block below prior to starting the exercise. The skeleton code has been provided for you, Edit only the cleanFiles function. | #Run this prior to starting the exercise
from random import randint as rnd
memReg = 'members.txt'
exReg = 'inactive.txt'
fee =('yes','no')
def genFiles(current,old):
with open(current,'w+') as writefile:
writefile.write('Membership No Date Joined Active \n')
data = "{:^13} {:<11} {:<6}\n"
for rowno in range(20):
date = str(rnd(2015,2020))+ '-' + str(rnd(1,12))+'-'+str(rnd(1,25))
writefile.write(data.format(rnd(10000,99999),date,fee[rnd(0,1)]))
with open(old,'w+') as writefile:
writefile.write('Membership No Date Joined Active \n')
data = "{:^13} {:<11} {:<6}\n"
for rowno in range(3):
date = str(rnd(2015,2020))+ '-' + str(rnd(1,12))+'-'+str(rnd(1,25))
writefile.write(data.format(rnd(10000,99999),date,fee[1]))
genFiles(memReg,exReg)
| _____no_output_____ | MIT | Python for Data Science, AI & Development/4. Working with Data in Python/Writing Files with Open.ipynb | aqafridi/Data-Analytics |
Start your solution below: |
def cleanFiles(currentMem,exMem):
'''
currentMem: File containing list of current members
exMem: File containing list of old members
Removes all rows from currentMem containing 'no' and appends them to exMem
'''
pass
# Code to help you see the files
# Leave as is
memReg = 'members.txt'
exReg = 'inactive.txt'
cleanFiles(memReg,exReg)
headers = "Membership No Date Joined Active \n"
with open(memReg,'r') as readFile:
print("Active Members: \n\n")
print(readFile.read())
with open(exReg,'r') as readFile:
print("Inactive Members: \n\n")
print(readFile.read())
| _____no_output_____ | MIT | Python for Data Science, AI & Development/4. Working with Data in Python/Writing Files with Open.ipynb | aqafridi/Data-Analytics |
Run the following to verify your code: | def testMsg(passed):
if passed:
return 'Test Passed'
else :
return 'Test Failed'
testWrite = "testWrite.txt"
testAppend = "testAppend.txt"
passed = True
genFiles(testWrite,testAppend)
with open(testWrite,'r') as file:
ogWrite = file.readlines()
with open(testAppend,'r') as file:
ogAppend = file.readlines()
try:
cleanFiles(testWrite,testAppend)
except:
print('Error')
with open(testWrite,'r') as file:
clWrite = file.readlines()
with open(testAppend,'r') as file:
clAppend = file.readlines()
# checking if total no of rows is same, including headers
if (len(ogWrite) + len(ogAppend) != len(clWrite) + len(clAppend)):
print("The number of rows do not add up. Make sure your final files have the same header and format.")
passed = False
for line in clWrite:
if 'no' in line:
passed = False
print("Inactive members in file")
break
else:
if line not in ogWrite:
print("Data in file does not match original file")
passed = False
print ("{}".format(testMsg(passed)))
| _____no_output_____ | MIT | Python for Data Science, AI & Development/4. Working with Data in Python/Writing Files with Open.ipynb | aqafridi/Data-Analytics |
Predict house price in America> Analyse and predict on house price dataset.- toc: true - badges: true- comments: true- categories: [self-taught]- image: images/chart-preview.png Introduction | import pandas as pd
pd.options.display.max_columns = 999
import numpy as np
import matplotlib.pyplot as plt
from sklearn.model_selection import KFold
from sklearn.metrics import mean_squared_error
from sklearn import linear_model
from sklearn.model_selection import KFold
df = pd.read_csv("AmesHousing.tsv", delimiter="\t")
def transform_features(df):
return df
def select_features(df):
return df[["Gr Liv Area", "SalePrice"]]
def train_and_test(df):
train = df[:1460]
test = df[1460:]
## You can use `pd.DataFrame.select_dtypes()` to specify column types
## and return only those columns as a data frame.
numeric_train = train.select_dtypes(include=['integer', 'float'])
numeric_test = test.select_dtypes(include=['integer', 'float'])
## You can use `pd.Series.drop()` to drop a value.
features = numeric_train.columns.drop("SalePrice")
lr = linear_model.LinearRegression()
lr.fit(train[features], train["SalePrice"])
predictions = lr.predict(test[features])
mse = mean_squared_error(test["SalePrice"], predictions)
rmse = np.sqrt(mse)
return rmse
transform_df = transform_features(df)
filtered_df = select_features(transform_df)
rmse = train_and_test(filtered_df)
rmse | _____no_output_____ | Apache-2.0 | _notebooks/2017-09-15-predict-house-price.ipynb | phucnsp/blog |
Feature Engineering Handle missing values: All columns: Drop any with 5% or more missing values for now. Text columns: Drop any with 1 or more missing values for now. Numerical columns: For columns with missing values, fill in with the most common value in that column 1: All columns: Drop any with 5% or more missing values for now. | ## Series object: column name -> number of missing values
num_missing = df.isnull().sum()
# Filter Series to columns containing >5% missing values
drop_missing_cols = num_missing[(num_missing > len(df)/20)].sort_values()
# Drop those columns from the data frame. Note the use of the .index accessor
df = df.drop(drop_missing_cols.index, axis=1)
## Series object: column name -> number of missing values
text_mv_counts = df.select_dtypes(include=['object']).isnull().sum().sort_values(ascending=False)
## Filter Series to columns containing *any* missing values
drop_missing_cols_2 = text_mv_counts[text_mv_counts > 0]
df = df.drop(drop_missing_cols_2.index, axis=1)
## Compute column-wise missing value counts
num_missing = df.select_dtypes(include=['int', 'float']).isnull().sum()
fixable_numeric_cols = num_missing[(num_missing < len(df)/20) & (num_missing > 0)].sort_values()
fixable_numeric_cols
## Compute the most common value for each column in `fixable_nmeric_missing_cols`.
replacement_values_dict = df[fixable_numeric_cols.index].mode().to_dict(orient='records')[0]
replacement_values_dict
## Use `pd.DataFrame.fillna()` to replace missing values.
df = df.fillna(replacement_values_dict)
## Verify that every column has 0 missing values
df.isnull().sum().value_counts()
years_sold = df['Yr Sold'] - df['Year Built']
years_sold[years_sold < 0]
years_since_remod = df['Yr Sold'] - df['Year Remod/Add']
years_since_remod[years_since_remod < 0]
## Create new columns
df['Years Before Sale'] = years_sold
df['Years Since Remod'] = years_since_remod
## Drop rows with negative values for both of these new features
df = df.drop([1702, 2180, 2181], axis=0)
## No longer need original year columns
df = df.drop(["Year Built", "Year Remod/Add"], axis = 1) | _____no_output_____ | Apache-2.0 | _notebooks/2017-09-15-predict-house-price.ipynb | phucnsp/blog |
Drop columns that: a. that aren't useful for ML b. leak data about the final sale | ## Drop columns that aren't useful for ML
df = df.drop(["PID", "Order"], axis=1)
## Drop columns that leak info about the final sale
df = df.drop(["Mo Sold", "Sale Condition", "Sale Type", "Yr Sold"], axis=1) | _____no_output_____ | Apache-2.0 | _notebooks/2017-09-15-predict-house-price.ipynb | phucnsp/blog |
Let's update transform_features() | def transform_features(df):
num_missing = df.isnull().sum()
drop_missing_cols = num_missing[(num_missing > len(df)/20)].sort_values()
df = df.drop(drop_missing_cols.index, axis=1)
text_mv_counts = df.select_dtypes(include=['object']).isnull().sum().sort_values(ascending=False)
drop_missing_cols_2 = text_mv_counts[text_mv_counts > 0]
df = df.drop(drop_missing_cols_2.index, axis=1)
num_missing = df.select_dtypes(include=['int', 'float']).isnull().sum()
fixable_numeric_cols = num_missing[(num_missing < len(df)/20) & (num_missing > 0)].sort_values()
replacement_values_dict = df[fixable_numeric_cols.index].mode().to_dict(orient='records')[0]
df = df.fillna(replacement_values_dict)
years_sold = df['Yr Sold'] - df['Year Built']
years_since_remod = df['Yr Sold'] - df['Year Remod/Add']
df['Years Before Sale'] = years_sold
df['Years Since Remod'] = years_since_remod
df = df.drop([1702, 2180, 2181], axis=0)
df = df.drop(["PID", "Order", "Mo Sold", "Sale Condition", "Sale Type", "Year Built", "Year Remod/Add"], axis=1)
return df
def select_features(df):
return df[["Gr Liv Area", "SalePrice"]]
def train_and_test(df):
train = df[:1460]
test = df[1460:]
## You can use `pd.DataFrame.select_dtypes()` to specify column types
## and return only those columns as a data frame.
numeric_train = train.select_dtypes(include=['integer', 'float'])
numeric_test = test.select_dtypes(include=['integer', 'float'])
## You can use `pd.Series.drop()` to drop a value.
features = numeric_train.columns.drop("SalePrice")
lr = linear_model.LinearRegression()
lr.fit(train[features], train["SalePrice"])
predictions = lr.predict(test[features])
mse = mean_squared_error(test["SalePrice"], predictions)
rmse = np.sqrt(mse)
return rmse
df = pd.read_csv("AmesHousing.tsv", delimiter="\t")
transform_df = transform_features(df)
filtered_df = select_features(transform_df)
rmse = train_and_test(filtered_df)
rmse | _____no_output_____ | Apache-2.0 | _notebooks/2017-09-15-predict-house-price.ipynb | phucnsp/blog |
Feature Selection | numerical_df = transform_df.select_dtypes(include=['int', 'float'])
numerical_df
abs_corr_coeffs = numerical_df.corr()['SalePrice'].abs().sort_values()
abs_corr_coeffs
## Let's only keep columns with a correlation coefficient of larger than 0.4 (arbitrary, worth experimenting later!)
abs_corr_coeffs[abs_corr_coeffs > 0.4]
## Drop columns with less than 0.4 correlation with SalePrice
transform_df = transform_df.drop(abs_corr_coeffs[abs_corr_coeffs < 0.4].index, axis=1) | _____no_output_____ | Apache-2.0 | _notebooks/2017-09-15-predict-house-price.ipynb | phucnsp/blog |
Which categorical columns should we keep? | ## Create a list of column names from documentation that are *meant* to be categorical
nominal_features = ["PID", "MS SubClass", "MS Zoning", "Street", "Alley", "Land Contour", "Lot Config", "Neighborhood",
"Condition 1", "Condition 2", "Bldg Type", "House Style", "Roof Style", "Roof Matl", "Exterior 1st",
"Exterior 2nd", "Mas Vnr Type", "Foundation", "Heating", "Central Air", "Garage Type",
"Misc Feature", "Sale Type", "Sale Condition"] | _____no_output_____ | Apache-2.0 | _notebooks/2017-09-15-predict-house-price.ipynb | phucnsp/blog |
Which columns are currently numerical but need to be encoded as categorical instead (because the numbers don't have any semantic meaning)? If a categorical column has hundreds of unique values (or categories), should we keep it? When we dummy code this column, hundreds of columns will need to be added back to the data frame. | ## Which categorical columns have we still carried with us? We'll test tehse
transform_cat_cols = []
for col in nominal_features:
if col in transform_df.columns:
transform_cat_cols.append(col)
## How many unique values in each categorical column?
uniqueness_counts = transform_df[transform_cat_cols].apply(lambda col: len(col.value_counts())).sort_values()
## Aribtrary cutoff of 10 unique values (worth experimenting)
drop_nonuniq_cols = uniqueness_counts[uniqueness_counts > 10].index
transform_df = transform_df.drop(drop_nonuniq_cols, axis=1)
## Select just the remaining text columns and convert to categorical
text_cols = transform_df.select_dtypes(include=['object'])
for col in text_cols:
transform_df[col] = transform_df[col].astype('category')
## Create dummy columns and add back to the dataframe!
transform_df = pd.concat([
transform_df,
pd.get_dummies(transform_df.select_dtypes(include=['category']))
], axis=1) | _____no_output_____ | Apache-2.0 | _notebooks/2017-09-15-predict-house-price.ipynb | phucnsp/blog |
Update select_features() | def transform_features(df):
num_missing = df.isnull().sum()
drop_missing_cols = num_missing[(num_missing > len(df)/20)].sort_values()
df = df.drop(drop_missing_cols.index, axis=1)
text_mv_counts = df.select_dtypes(include=['object']).isnull().sum().sort_values(ascending=False)
drop_missing_cols_2 = text_mv_counts[text_mv_counts > 0]
df = df.drop(drop_missing_cols_2.index, axis=1)
num_missing = df.select_dtypes(include=['int', 'float']).isnull().sum()
fixable_numeric_cols = num_missing[(num_missing < len(df)/20) & (num_missing > 0)].sort_values()
replacement_values_dict = df[fixable_numeric_cols.index].mode().to_dict(orient='records')[0]
df = df.fillna(replacement_values_dict)
years_sold = df['Yr Sold'] - df['Year Built']
years_since_remod = df['Yr Sold'] - df['Year Remod/Add']
df['Years Before Sale'] = years_sold
df['Years Since Remod'] = years_since_remod
df = df.drop([1702, 2180, 2181], axis=0)
df = df.drop(["PID", "Order", "Mo Sold", "Sale Condition", "Sale Type", "Year Built", "Year Remod/Add"], axis=1)
return df
def select_features(df, coeff_threshold=0.4, uniq_threshold=10):
numerical_df = df.select_dtypes(include=['int', 'float'])
abs_corr_coeffs = numerical_df.corr()['SalePrice'].abs().sort_values()
df = df.drop(abs_corr_coeffs[abs_corr_coeffs < coeff_threshold].index, axis=1)
nominal_features = ["PID", "MS SubClass", "MS Zoning", "Street", "Alley", "Land Contour", "Lot Config", "Neighborhood",
"Condition 1", "Condition 2", "Bldg Type", "House Style", "Roof Style", "Roof Matl", "Exterior 1st",
"Exterior 2nd", "Mas Vnr Type", "Foundation", "Heating", "Central Air", "Garage Type",
"Misc Feature", "Sale Type", "Sale Condition"]
transform_cat_cols = []
for col in nominal_features:
if col in df.columns:
transform_cat_cols.append(col)
uniqueness_counts = df[transform_cat_cols].apply(lambda col: len(col.value_counts())).sort_values()
drop_nonuniq_cols = uniqueness_counts[uniqueness_counts > 10].index
df = df.drop(drop_nonuniq_cols, axis=1)
text_cols = df.select_dtypes(include=['object'])
for col in text_cols:
df[col] = df[col].astype('category')
df = pd.concat([df, pd.get_dummies(df.select_dtypes(include=['category']))], axis=1)
return df
def train_and_test(df, k=0):
numeric_df = df.select_dtypes(include=['integer', 'float'])
features = numeric_df.columns.drop("SalePrice")
lr = linear_model.LinearRegression()
if k == 0:
train = df[:1460]
test = df[1460:]
lr.fit(train[features], train["SalePrice"])
predictions = lr.predict(test[features])
mse = mean_squared_error(test["SalePrice"], predictions)
rmse = np.sqrt(mse)
return rmse
if k == 1:
# Randomize *all* rows (frac=1) from `df` and return
shuffled_df = df.sample(frac=1, )
train = df[:1460]
test = df[1460:]
lr.fit(train[features], train["SalePrice"])
predictions_one = lr.predict(test[features])
mse_one = mean_squared_error(test["SalePrice"], predictions_one)
rmse_one = np.sqrt(mse_one)
lr.fit(test[features], test["SalePrice"])
predictions_two = lr.predict(train[features])
mse_two = mean_squared_error(train["SalePrice"], predictions_two)
rmse_two = np.sqrt(mse_two)
avg_rmse = np.mean([rmse_one, rmse_two])
print(rmse_one)
print(rmse_two)
return avg_rmse
else:
kf = KFold(n_splits=k, shuffle=True)
rmse_values = []
for train_index, test_index, in kf.split(df):
train = df.iloc[train_index]
test = df.iloc[test_index]
lr.fit(train[features], train["SalePrice"])
predictions = lr.predict(test[features])
mse = mean_squared_error(test["SalePrice"], predictions)
rmse = np.sqrt(mse)
rmse_values.append(rmse)
print(rmse_values)
avg_rmse = np.mean(rmse_values)
return avg_rmse
df = pd.read_csv("AmesHousing.tsv", delimiter="\t")
transform_df = transform_features(df)
filtered_df = select_features(transform_df)
rmse = train_and_test(filtered_df, k=4)
rmse | [25761.875549560471, 36527.812968130842, 24956.485193881424, 28486.738135675929]
| Apache-2.0 | _notebooks/2017-09-15-predict-house-price.ipynb | phucnsp/blog |
FastPitch: Voice Modification with Pre-defined Pitch Transformations The [FastPitch](https://arxiv.org/abs/2006.06873) model is based on the [FastSpeech](https://arxiv.org/abs/1905.09263) model. Similarly to [FastSpeech2](https://arxiv.org/abs/2006.04558), which has been developed concurrently, it learns to predict the pitch contour and conditions the generation on such contour.The simple mechanism of predicting the pitch on grapheme-level (rather than frame-level, as FastSpeech2 does) allows to easily alter the pitch during synthesis. FastPitch can thus change the perceived emotional state of the speaker, or slightly emphasise certain lexical units. Requirements Run the notebook inside the container. By default the container forwards port `8888`.```bash scripts/docker/interactive.sh inside the containercd notebooksjupyter notebook --ip='*' --port=8888```Please refer the Requirement section in `README.md` for more details and running outside the container. | import os
assert os.getcwd().split('/')[-1] == 'notebooks' | _____no_output_____ | MIT | SpeechSynthesis/FastPitch/notebooks/FastPitch_voice_modification.ipynb | eba472/mongolian_tts |
Generate audio samples Training a FastPitch model from scrath takes 3 to 27 hours depending on the type and number of GPUs, performance numbers can be found in Section "Training performance results" in `README.md`. Therefore, to save the time of running this notebook, we recommend to download the pretrained FastPitch checkpoints on NGC for inference.You can find FP32 checkpoint at [NGC](https://ngc.nvidia.com/catalog/models/nvidia:fastpitch_pyt_fp32_ckpt_v1/files) , and AMP (Automatic Mixed Precision) checkpoint at [NGC](https://ngc.nvidia.com/catalog/models/nvidia:fastpitch_pyt_amp_ckpt_v1/files).To synthesize audio, you will need a WaveGlow model, which generates waveforms based on mel-spectrograms generated by FastPitch.You can download a pre-trained WaveGlow AMP model at [NGC](https://ngc.nvidia.com/catalog/models/nvidia:waveglow256pyt_fp16). | ! mkdir -p output
! MODEL_DIR='../pretrained_models' ../scripts/download_fastpitch.sh
! MODEL_DIR='../pretrained_models' ../scripts/download_waveglow.sh | _____no_output_____ | MIT | SpeechSynthesis/FastPitch/notebooks/FastPitch_voice_modification.ipynb | eba472/mongolian_tts |
You can perform inference using the respective checkpoints that are passed as `--fastpitch` and `--waveglow` arguments. Next, you will use FastPitch model to generate audio samples for input text, including the basic version and the variations i npace, fade out, and pitch transforms, etc. | import IPython
# store paths in aux variables
fastp = '../pretrained_models/fastpitch/nvidia_fastpitch_200518.pt'
waveg = '../pretrained_models/waveglow/waveglow_1076430_14000_amp.pt'
flags = f'--cuda --fastpitch {fastp} --waveglow {waveg} --wn-channels 256' | _____no_output_____ | MIT | SpeechSynthesis/FastPitch/notebooks/FastPitch_voice_modification.ipynb | eba472/mongolian_tts |
1. Basic speech synthesis You need to create an input file with some text, or just input the text in the below cell: | %%writefile text.txt
The forms of printed letters should be beautiful, and that their arrangement on the page should be reasonable and a help to the shapeliness of the letters themselves. | _____no_output_____ | MIT | SpeechSynthesis/FastPitch/notebooks/FastPitch_voice_modification.ipynb | eba472/mongolian_tts |
Run the script below to generate audio from the input text file: | # basic systhesis
!python ../inference.py {flags} -i text.txt -o output/original > /dev/null
IPython.display.Audio("output/original/audio_0.wav") | _____no_output_____ | MIT | SpeechSynthesis/FastPitch/notebooks/FastPitch_voice_modification.ipynb | eba472/mongolian_tts |
2. Add variations to the generated speech FastPitch allows us to exert additional control over the synthesized utterances, the key parameters are the pace, fade out, and pitch transforms in particular. 2.1 Pace FastPitch allows you to linearly adjust the pace of synthesized speech, similar to [FastSpeech](https://arxiv.org/abs/1905.09263) model. For instance, pass --pace 0.5 for a twofold decrease in speed, --pace 1.0 = unchanged. | # Change the pace of speech to double with --pace 0.5
# (1.0 = unchanged)
!python ../inference.py {flags} -i text.txt -o output/pace --pace 0.5 > /dev/null
IPython.display.Audio("output/pace/audio_0.wav") | _____no_output_____ | MIT | SpeechSynthesis/FastPitch/notebooks/FastPitch_voice_modification.ipynb | eba472/mongolian_tts |
2.2 Raise or lower the pitch For every input character, the model predicts a pitch cue - an average pitch over a character in Hz. Pitch can be adjusted by transforming those pitch cues. A few simple examples are provided below. | # Raise/lower pitch by --pitch-transform-shift <Hz>
# Synthesize with a -50 Hz shift
!python ../inference.py {flags} -i text.txt -o output/riselowpitch --pitch-transform-shift -50 > /dev/null
IPython.display.Audio("output/riselowpitch/audio_0.wav") | _____no_output_____ | MIT | SpeechSynthesis/FastPitch/notebooks/FastPitch_voice_modification.ipynb | eba472/mongolian_tts |
2.3 Flatten the pitch | # Flatten the pitch to a constant value with --pitch-transform-flatten
!python ../inference.py {flags} -i text.txt -o output/flattenpitch --pitch-transform-flatten > /dev/null
IPython.display.Audio("output/flattenpitch/audio_0.wav") | _____no_output_____ | MIT | SpeechSynthesis/FastPitch/notebooks/FastPitch_voice_modification.ipynb | eba472/mongolian_tts |
2.4 Invert the pitch | # Invert pitch wrt. to the mean pitch with --pitch-transform-invert
!python ../inference.py {flags} -i text.txt -o output/invertpitch --pitch-transform-invert > /dev/null
IPython.display.Audio("output/invertpitch/audio_0.wav") | _____no_output_____ | MIT | SpeechSynthesis/FastPitch/notebooks/FastPitch_voice_modification.ipynb | eba472/mongolian_tts |
2.5 Amplify the pitch | # Amplify pitch wrt. to the mean pitch with --pitch-transform-amplify 2.0
# values in the (1.0, 3.0) range work the best
!python ../inference.py {flags} -i text.txt -o output/amplifypitch --pitch-transform-amplify 2.0 > /dev/null
IPython.display.Audio("output/amplifypitch/audio_0.wav") | _____no_output_____ | MIT | SpeechSynthesis/FastPitch/notebooks/FastPitch_voice_modification.ipynb | eba472/mongolian_tts |
2.6 Combine the flags The flags can be combined. You can find all the available options by calling python inference.py --help. | !python ../inference.py --help | _____no_output_____ | MIT | SpeechSynthesis/FastPitch/notebooks/FastPitch_voice_modification.ipynb | eba472/mongolian_tts |
Below example shows how to generate an audio with a combination of the flags --pace --pitch-transform-flatten --pitch-transform-shift --pitch-transform-invert --pitch-transform-amplify | # Dobuble the speed and combine multiple transformations
!python ../inference.py {flags} -i text.txt -o output/combine \
--pace 2.0 --pitch-transform-flatten --pitch-transform-shift 50 \
--pitch-transform-invert --pitch-transform-amplify 1.5 > /dev/null
IPython.display.Audio("output/combine/audio_0.wav") | _____no_output_____ | MIT | SpeechSynthesis/FastPitch/notebooks/FastPitch_voice_modification.ipynb | eba472/mongolian_tts |
3. Inference performance benchmark | # Benchmark inference using AMP
!python ../inference.py {flags} \
--include-warmup --batch-size 8 --repeats 100 --torchscript --amp \
-i ../phrases/benchmark_8_128.tsv -o output/benchmark | _____no_output_____ | MIT | SpeechSynthesis/FastPitch/notebooks/FastPitch_voice_modification.ipynb | eba472/mongolian_tts |
k-NN, Function Expectation, Density Estimation | from experiment_framework.helpers import build_convergence_curve_pipeline
from empirical_privacy.one_bit_sum import GenSampleOneBitSum
# from empirical_privacy import one_bit_sum_joblib as one_bit_sum
# from empirical_privacy import lsdd
# reload(one_bit_sum)
def B_pmf(k, n, p):
return binom(n, p).pmf(k)
def B0_pmf(k, n, p):
return B_pmf(k, n-1, p)
def B1_pmf(k, n, p):
return B_pmf(k-1, n-1, p)
def sd(N, P):
return 0.5*np.sum(abs(B0_pmf(i, N, P) - B1_pmf(i, N, P)) for i in range(N+1))
def optimal_correctness(n, p):
return 0.5 + 0.5*sd(n, p)
n_max = 2**10
ntri=30
n=7
p=0.5
sd(n,p)
B0 = [B0_pmf(i, n, p) for i in range(n+1)]
B1 = [B1_pmf(i, n, p) for i in range(n+1)]
dif = np.abs(np.array(B0)-np.array(B1))
sdv = 0.5*np.sum(dif)
pc = 0.5+0.5*sdv
print(f'n={n} coin flips p={p} probability of heads'\
'\nB0 has first outcome=0, B1 has first outcome=1')
print(f'Statistic is the total number of heads sum')
print(f'N_heads=\t{" ".join(np.arange(n+1).astype(str))}')
print(f'PMF of B0=\t{B0}\nPMF of B1=\t{B1}')
print(f'|B0-B1|=\t{dif}')
print(f'sd = 0.5 * sum(|B0-B1|) = {sdv}')
print(f'P(Correct) = 0.5 + 0.5*sd = {pc}')
ccc_kwargs = {
'confidence_interval_width':10,
'n_max':2**13,
'dataset_settings' : {
'n_trials':n,
'prob_success':p,
'gen_distr_type':'binom'
},
'validation_set_size' : 2000
}
CCCs = []
Fits = ['knn', 'density', 'expectation']
for fit in Fits:
CCCs.append(build_convergence_curve_pipeline(
GenSampleOneBitSum,
gensample_kwargs = {'generate_in_batch':True},
fitter=fit,
fitter_kwargs={} if fit=='knn' else {'statistic_column':0}
)(**ccc_kwargs)
)
luigi.build(CCCs, local_scheduler=True, workers=4, log_level='ERROR')
colors = cm.Accent(np.linspace(0,1,len(CCCs)+1))
ax = plt.figure(figsize=(10,5))
ax = plt.gca()
leg_handles = []
for (i, CC) in enumerate(CCCs):
with CC.output().open() as f:
res = pickle.load(f)
handle=sns.tsplot(res['sd_matrix'], ci='sd', color=colors[i], ax=ax, legend=False, time=res['training_set_sizes'])
j=0
for i in range(len(CCCs), 2*len(CCCs)):
handle.get_children()[i].set_label('{}'.format(Fits[j]))
j+=1
plt.semilogx()
plt.axhline(optimal_correctness(n, p), linestyle='--', color='r', label='_nolegend_')
plt.axhline(0.5, linestyle='-', color='b', label='_nolegend_')
plt.title('n={n} p={p} $\delta$={d:.3f}'.format(n=n, p=p, d=sd(n,p)), fontsize=20)
plt.xlabel('num samples')
plt.ylabel('Correctness Rate')
plt.legend(loc=(0,1.1))
| /opt/conda/lib/python3.6/site-packages/seaborn/timeseries.py:183: UserWarning: The `tsplot` function is deprecated and will be removed in a future release. Please update your code to use the new `lineplot` function.
warnings.warn(msg, UserWarning)
/opt/conda/lib/python3.6/site-packages/seaborn/timeseries.py:183: UserWarning: The `tsplot` function is deprecated and will be removed in a future release. Please update your code to use the new `lineplot` function.
warnings.warn(msg, UserWarning)
/opt/conda/lib/python3.6/site-packages/seaborn/timeseries.py:183: UserWarning: The `tsplot` function is deprecated and will be removed in a future release. Please update your code to use the new `lineplot` function.
warnings.warn(msg, UserWarning)
| MIT | Notebooks/development/1-bit sum.ipynb | maksimt/empirical_privacy |
Repeat the above using joblib to make sure the luigi implementation is correct | from math import ceil, log
one_bit_sum.n_jobs=1
N = int(ceil(log(n_max) / log(2)))
N_samples = np.logspace(4,N,num=N-3, base=2).astype(np.int)
ax = plt.figure(figsize=(10,5))
ax = plt.gca()
AlgArg = namedtuple('AlgArg', field_names=['f_handle', 'f_kwargs'])
algs = [
AlgArg(one_bit_sum.get_knn_correctness_rate_cached, {'neighbor_method':'sqrt'}),
AlgArg(one_bit_sum.get_knn_correctness_rate_cached, {'neighbor_method':'sqrt_random_tiebreak'}),
AlgArg(one_bit_sum.get_density_est_correctness_rate_cached, {'bandwidth_method':None}),
AlgArg(one_bit_sum.get_expectation_correctness_rate_cached, {'bandwidth_method':None}),
AlgArg(one_bit_sum.get_lsdd_correctness_rate_cached, {})
#AlgArg(one_bit_sum.get_knn_correctness_rate_cached, {'neighbor_method':'cv'})
]
colors = cm.Accent(np.linspace(0,1,len(algs)+1))
leg_handles = []
for (i,alg) in enumerate(algs):
res = one_bit_sum.get_res(n,p,ntri, alg.f_handle, alg.f_kwargs, n_max=n_max)
handle=sns.tsplot(res, ci='sd', color=colors[i], ax=ax, legend=False, time=N_samples)
# f, coef = get_fit(res, N_samples)
# print alg, coef
# lim = coef[0]
# plt.plot(N_samples, f(N_samples), linewidth=3)
# plt.text(N_samples[-1], lim, '{:.3f}'.format(lim),fontsize=16)
j=0
for i in range(len(algs), 2*len(algs)):
#print i, i/2-1 if i%2==0 else (i)/2
handle.get_children()[i].set_label('{} {}'.format(algs[j].f_handle.func.__name__, algs[j].f_kwargs))
j+=1
plt.semilogx()
plt.axhline(optimal_correctness(n, p), linestyle='--', color='r', label='_nolegend_')
plt.axhline(0.5, linestyle='-', color='b', label='_nolegend_')
plt.title('n={n} p={p} $\delta$={d:.3f}'.format(n=n, p=p, d=sd(n,p)), fontsize=20)
plt.xlabel('num samples')
plt.ylabel('Correctness Rate')
plt.legend(loc=(0,1.1))
#print ax.get_legend_handles_labels() | [Parallel(n_jobs=1)]: Done 1 out of 1 | elapsed: 0.5s remaining: 0.0s
[Parallel(n_jobs=1)]: Done 2 out of 2 | elapsed: 1.3s remaining: 0.0s
[Parallel(n_jobs=1)]: Done 3 out of 3 | elapsed: 2.0s remaining: 0.0s
[Parallel(n_jobs=1)]: Done 3 out of 3 | elapsed: 2.0s finished
/opt/conda/lib/python3.6/site-packages/seaborn/timeseries.py:183: UserWarning: The `tsplot` function is deprecated and will be removed in a future release. Please update your code to use the new `lineplot` function.
warnings.warn(msg, UserWarning)
[Parallel(n_jobs=1)]: Done 1 out of 1 | elapsed: 0.7s remaining: 0.0s
[Parallel(n_jobs=1)]: Done 2 out of 2 | elapsed: 1.3s remaining: 0.0s
[Parallel(n_jobs=1)]: Done 3 out of 3 | elapsed: 2.1s remaining: 0.0s
[Parallel(n_jobs=1)]: Done 3 out of 3 | elapsed: 2.1s finished
/opt/conda/lib/python3.6/site-packages/seaborn/timeseries.py:183: UserWarning: The `tsplot` function is deprecated and will be removed in a future release. Please update your code to use the new `lineplot` function.
warnings.warn(msg, UserWarning)
[Parallel(n_jobs=1)]: Done 1 out of 1 | elapsed: 1.9s remaining: 0.0s
[Parallel(n_jobs=1)]: Done 2 out of 2 | elapsed: 3.5s remaining: 0.0s
[Parallel(n_jobs=1)]: Done 3 out of 3 | elapsed: 5.1s remaining: 0.0s
[Parallel(n_jobs=1)]: Done 3 out of 3 | elapsed: 5.1s finished
/opt/conda/lib/python3.6/site-packages/seaborn/timeseries.py:183: UserWarning: The `tsplot` function is deprecated and will be removed in a future release. Please update your code to use the new `lineplot` function.
warnings.warn(msg, UserWarning)
[Parallel(n_jobs=1)]: Done 1 out of 1 | elapsed: 0.8s remaining: 0.0s
[Parallel(n_jobs=1)]: Done 2 out of 2 | elapsed: 1.4s remaining: 0.0s
[Parallel(n_jobs=1)]: Done 3 out of 3 | elapsed: 2.0s remaining: 0.0s
[Parallel(n_jobs=1)]: Done 3 out of 3 | elapsed: 2.0s finished
/opt/conda/lib/python3.6/site-packages/seaborn/timeseries.py:183: UserWarning: The `tsplot` function is deprecated and will be removed in a future release. Please update your code to use the new `lineplot` function.
warnings.warn(msg, UserWarning)
[Parallel(n_jobs=1)]: Done 1 out of 1 | elapsed: 7.4s remaining: 0.0s
[Parallel(n_jobs=1)]: Done 2 out of 2 | elapsed: 14.3s remaining: 0.0s
[Parallel(n_jobs=1)]: Done 3 out of 3 | elapsed: 22.8s remaining: 0.0s
[Parallel(n_jobs=1)]: Done 3 out of 3 | elapsed: 22.8s finished
/opt/conda/lib/python3.6/site-packages/seaborn/timeseries.py:183: UserWarning: The `tsplot` function is deprecated and will be removed in a future release. Please update your code to use the new `lineplot` function.
warnings.warn(msg, UserWarning)
| MIT | Notebooks/development/1-bit sum.ipynb | maksimt/empirical_privacy |
Timing GenSamples Without halving: 7.5secWith halving: 8.1sec (i.e. not much overhead) | from luigi_utils.sampling_framework import GenSamples
import time
class GS(GenSamples(GenSampleOneBitSum, generate_in_batch=True)):
pass
GSi = GS(dataset_settings = ccc_kwargs['dataset_settings'],
random_seed='0',
generate_positive_samples=True,
num_samples=2**15)
start = time.time()
luigi.build([GSi], local_scheduler=True, workers=8, log_level='ERROR')
cputime = time.time() - start
print(cputime)
res['training_set_sizes'].shape
np.concatenate((np.array([]), np.array([1,2,3]))) | _____no_output_____ | MIT | Notebooks/development/1-bit sum.ipynb | maksimt/empirical_privacy |
More exp | def get_fit(res, N_samples):
ntri, nsamp = res.shape
sqrt2 = np.sqrt(2)
Xlsq = np.hstack((np.ones((nsamp,1)),
sqrt2/(N_samples.astype(np.float)**0.25)[:, np.newaxis]))
y = 1.0 - res.reshape((nsamp*ntri, 1))
Xlsq = reduce(lambda x,y: np.vstack((x,y)), [Xlsq]*ntri)
coef = np.linalg.lstsq(Xlsq, y)[0].ravel()
f = lambda n: 1.0 - coef[0] - coef[1]*sqrt2/n.astype(np.float)**0.25, coef
return f
trial=0
num_samples=2**11
bandwidth_method=None
from scipy.stats import gaussian_kde
X0, X1, y0, y1 = one_bit_sum.gen_data(n, p, num_samples, trial)
X0 = X0.ravel()
X1 = X1.ravel()
bw = None
if hasattr(bandwidth_method, '__call__'):
bw = float(bandwidth_method(num_samples)) / num_samples # eg log
if type(bandwidth_method) == float:
bw = num_samples**(1-bandwidth_method)
f0 = gaussian_kde(X0, bw_method = bw)
f1 = gaussian_kde(X1, bw_method = bw)
#Omega = np.unique(np.concatenate((X0, X1)))
_min = 0
_max = n
x = np.linspace(_min, _max, num=10*num_samples)
print('difference of densities=',0.5 + 0.5 * 0.5 * np.mean(np.abs(f0(x)-f1(x))))
denom = f0(x)+f1(x)
numer = np.abs(f0(x)-f1(x))
print('expectation = ',0.5 + 0.5*np.mean(numer/denom)) | _____no_output_____ | MIT | Notebooks/development/1-bit sum.ipynb | maksimt/empirical_privacy |
Uniforml distributed random variables $$g_0 = U[0,0.5]+\sum_{i=1}^{n-1} U[0,1]$$$$g_1 = U[0.5,1.0]+\sum_{i=1}^{n-1} U[0,1]$$ Let $\mu_n = \frac{n-1}{2}$ and $\sigma_n = \sqrt{\frac{n-0.75}{12}}$By the CLT $g_0\sim N(\mu_n+0.25, \sigma_n)$ and $g_1\sim N(\mu_n+0.75, \sigma_n)$. | from math import sqrt
n=3
x = np.linspace(n/2.0-sqrt(n), n/2.0+sqrt(n))
sigma = sqrt((n-0.75)/12.0)
sqrt2 = sqrt(2)
mu = (n-1.0)/2
def g0_pdf(x):
return norm.pdf(x, loc=mu+0.25, scale=sigma)
def g1_pdf(x):
return norm.pdf(x, loc=mu+0.75, scale=sigma)
def d_pdf(x):
return norm.pdf(x, loc=-0.5, scale=sigma*sqrt2)
def g_int(n):
sigma = sqrt((n-0.75)/12.0)
mu = (n-1.0)/2
N0 = norm(loc=mu+0.25, scale=sigma)
N1 = norm(loc=mu+0.75, scale=sigma)
I0 = N0.cdf(n*0.5)-N0.cdf(0)
I1 = N1.cdf(n*0.5)-N1.cdf(0)
return 2*(I0-I1)
def g_stat_dist(n):
return 0.5 * g_int(n)
def g_optimal_correctness(n):
return 0.5 + 0.5*g_stat_dist(n)
plt.plot(x, g0_pdf(x), label='$g_0$')
plt.plot(x, g1_pdf(x), label='$g_1$')
#plt.plot(x, d_pdf(x), label='$d$')
plt.axvline(x=n/2.0, color='r')
assert g0_pdf(n/2.0)==g1_pdf(n/2.0)
plt.legend()
print(g_optimal_correctness(n))
from math import ceil, log
if n_max >= 2**13:
one_bit_sum.n_jobs=1
else:
one_bit_sum.n_jobs=-1
N = int(ceil(log(n_max) / log(2)))
N_samples = np.logspace(4,N,num=N-3, base=2).astype(np.int)
ax = plt.figure(figsize=(10,5))
ax = plt.gca()
AlgArg = namedtuple('AlgArg', field_names=['f_handle', 'f_kwargs'])
algs = [
AlgArg(one_bit_sum.get_knn_correctness_rate_cached, {'neighbor_method':'sqrt'}),
AlgArg(one_bit_sum.get_knn_correctness_rate_cached, {'neighbor_method':'sqrt_random_tiebreak'}),
AlgArg(one_bit_sum.get_density_est_correctness_rate_cached, {'bandwidth_method':None}),
AlgArg(one_bit_sum.get_expectation_correctness_rate_cached, {'bandwidth_method':None}),
AlgArg(one_bit_sum.get_lsdd_correctness_rate_cached, {})
#AlgArg(one_bit_sum.get_knn_correctness_rate_cached, {'neighbor_method':'cv'})
]
for A in algs:
A.f_kwargs['type']='norm'
colors = cm.Accent(np.linspace(0,1,len(algs)+1))
leg_handles = []
for (i,alg) in enumerate(algs):
res = one_bit_sum.get_res(n,p,ntri, alg.f_handle, alg.f_kwargs, n_max=n_max)
handle=sns.tsplot(res, ci='sd', color=colors[i], ax=ax, legend=False, time=N_samples)
# f, coef = get_fit(res, N_samples)
# print alg, coef
# lim = coef[0]
# plt.plot(N_samples, f(N_samples), linewidth=3)
# plt.text(N_samples[-1], lim, '{:.3f}'.format(lim),fontsize=16)
j=0
for i in range(len(algs), 2*len(algs)):
#print i, i/2-1 if i%2==0 else (i)/2
handle.get_children()[i].set_label(algs[j].f_handle.func.__name__)
j+=1
#print handle.get_children()[i].get_label()
plt.semilogx()
plt.axhline(g_optimal_correctness(n), linestyle='--', color='r', label='_nolegend_')
plt.axhline(0.5, linestyle='-', color='b', label='_nolegend_')
plt.title('n={n} $\delta$={d:.3f}'.format(n=n, d=g_stat_dist(n)), fontsize=20)
plt.xlabel('num samples')
plt.ylabel('Correctness Rate')
plt.legend(loc=(1.1,0))
#print ax.get_legend_handles_labels()
true_value = g_optimal_correctness(n)
print(true_value)
trial=0
num_samples=2**15
bandwidth_method=None
from scipy.stats import gaussian_kde
X0, X1, y0, y1 = one_bit_sum.gen_data(n, p, num_samples, trial, type='norm')
X0 = X0.ravel()
X1 = X1.ravel()
bw = None
if hasattr(bandwidth_method, '__call__'):
bw = float(bandwidth_method(num_samples)) / num_samples # eg log
if type(bandwidth_method) == float:
bw = num_samples**(1-bandwidth_method)
f0 = gaussian_kde(X0, bw_method = bw)
f1 = gaussian_kde(X1, bw_method = bw)
#Omega = np.unique(np.concatenate((X0, X1)))
_min = 0
_max = n
x = np.linspace(_min, _max, num=num_samples)
print('difference of densities=',0.5 + 0.5 * 0.5 * integrate.quad(lambda x: np.abs(f0(x)-f1(x)), -np.inf, np.inf)[0])
X = np.concatenate((X0,X1))
f0x = f0(X)
f1x = f1(X)
denom = (f0x+f1x+np.spacing(1))
numer = np.abs(f0x-f1x)
print('expectation = ',0.5 + 0.5*np.mean(numer/denom))
print('exact=',g_optimal_correctness(n))
plt.plot(x, f0(x),label='$\hat g_0$', linestyle='--')
plt.plot(x, f1(x),label='$\hat g_1$', linestyle='--')
plt.plot(x, g0_pdf(x), label='$g_0$')
plt.plot(x, g1_pdf(x), label='$g_1$')
plt.legend(loc=(1.05,0)) | _____no_output_____ | MIT | Notebooks/development/1-bit sum.ipynb | maksimt/empirical_privacy |
Comparing different numerical integration techniques | to_int = [f0,f1]
print 'Quad'
# for (i,f) in enumerate(to_int):
# intr = integrate.quad(f, -np.inf, np.inf)
# print 'func={0} err={1:.3e}'.format(i, abs(1-intr[0]))
g_int(n)-integrate.quad(lambda x: np.abs(f0(x)-f1(x)), -np.inf, np.inf)[0]
to_int = [f0,f1]
print 'Quad'
g_int(n)-integrate.quad(lambda x: np.abs(f0(x)-f1(x)), -np.inf, np.inf)[0]
g_int(n)
print 'Simps'
def delta(x):
return np.abs(f0(x)-f1(x))
X = np.unique(np.concatenate((X0,X1)))
y = delta(X)
g_int(n)-integrate.simps(y,X)
import empirical_privacy.lsdd
rtv = lsdd.lsdd(X0[np.newaxis, :], X1[np.newaxis, :])
plt.hist(rtv[1])
np.mean(rtv[1]) | _____no_output_____ | MIT | Notebooks/development/1-bit sum.ipynb | maksimt/empirical_privacy |
Sympy-based analysis | import sympy as sy
n,k = sy.symbols('n k', integer=True)
#k = sy.Integer(k)
p = sy.symbols('p', real=True)
q=1-p
def binom_pmf(k, n, p):
return sy.binomial(n,k)*(p**k)*(q**(n-k))
def binom_cdf(x, n, p):
return sy.Sum([binom_pmf(j, n, p) for j in sy.Range(x+1)])
B0 = binom_pmf(k, n-1, p)
B1 = binom_pmf(k-1, n-1, p)
def stat_dist(N,P):
return 0.5*sum([sy.Abs(B0.subs([(n,N),(p,P), (k,i)])-B1.subs([(n,N),(p,P), (k,i)])) for i in range(N+1)])
def sd(N, P):
return 0.5*np.sum(abs(B0(i, N, P) - B1(i, N, P)) for i in range(N+1))
stat_dist(50,0.5)
sd(5000,0.5)
N=2
terms =[(B0.subs([(n,N), (k,i)]).simplify(),B1.subs([(n,N), (k,i)]).simplify()) for i in range(N+1)]
print terms
0.5*sum(map(lambda t: sy.Abs(t[0]-t[1]), terms)).subs([(p,0.5)])
stat_dist(4,0.5) | _____no_output_____ | MIT | Notebooks/development/1-bit sum.ipynb | maksimt/empirical_privacy |
Regression Week 2: Multiple Regression (gradient descent) In the first notebook we explored multiple regression using graphlab create. Now we will use graphlab along with numpy to solve for the regression weights with gradient descent.In this notebook we will cover estimating multiple regression weights via gradient descent. You will:* Add a constant column of 1's to a graphlab SFrame to account for the intercept* Convert an SFrame into a Numpy array* Write a predict_output() function using Numpy* Write a numpy function to compute the derivative of the regression weights with respect to a single feature* Write gradient descent function to compute the regression weights given an initial weight vector, step size and tolerance.* Use the gradient descent function to estimate regression weights for multiple features Fire up graphlab create Make sure you have the latest version of graphlab (>= 1.7) | import graphlab | _____no_output_____ | MIT | Machine_Learning_Regression/.ipynb_checkpoints/week-2-multiple-regression-assignment-2-blank-checkpoint.ipynb | nkmah2/ML_Uni_Washington_Coursera |
Load in house sales dataDataset is from house sales in King County, the region where the city of Seattle, WA is located. | sales = graphlab.SFrame('kc_house_data.gl/') | [INFO] [1;32m1449884188 : INFO: (initialize_globals_from_environment:282): Setting configuration variable GRAPHLAB_FILEIO_ALTERNATIVE_SSL_CERT_FILE to /home/nitin/anaconda/lib/python2.7/site-packages/certifi/cacert.pem
[0m[1;32m1449884188 : INFO: (initialize_globals_from_environment:282): Setting configuration variable GRAPHLAB_FILEIO_ALTERNATIVE_SSL_CERT_DIR to
[0mThis non-commercial license of GraphLab Create is assigned to [email protected] and will expire on October 14, 2016. For commercial licensing options, visit https://dato.com/buy/.
[INFO] Start server at: ipc:///tmp/graphlab_server-4201 - Server binary: /home/nitin/anaconda/lib/python2.7/site-packages/graphlab/unity_server - Server log: /tmp/graphlab_server_1449884188.log
[INFO] GraphLab Server Version: 1.7.1
| MIT | Machine_Learning_Regression/.ipynb_checkpoints/week-2-multiple-regression-assignment-2-blank-checkpoint.ipynb | nkmah2/ML_Uni_Washington_Coursera |
If we want to do any "feature engineering" like creating new features or adjusting existing ones we should do this directly using the SFrames as seen in the other Week 2 notebook. For this notebook, however, we will work with the existing features. Convert to Numpy Array Although SFrames offer a number of benefits to users (especially when using Big Data and built-in graphlab functions) in order to understand the details of the implementation of algorithms it's important to work with a library that allows for direct (and optimized) matrix operations. Numpy is a Python solution to work with matrices (or any multi-dimensional "array").Recall that the predicted value given the weights and the features is just the dot product between the feature and weight vector. Similarly, if we put all of the features row-by-row in a matrix then the predicted value for *all* the observations can be computed by right multiplying the "feature matrix" by the "weight vector". First we need to take the SFrame of our data and convert it into a 2D numpy array (also called a matrix). To do this we use graphlab's built in .to_dataframe() which converts the SFrame into a Pandas (another python library) dataframe. We can then use Panda's .as_matrix() to convert the dataframe into a numpy matrix. | import numpy as np # note this allows us to refer to numpy as np instead | _____no_output_____ | MIT | Machine_Learning_Regression/.ipynb_checkpoints/week-2-multiple-regression-assignment-2-blank-checkpoint.ipynb | nkmah2/ML_Uni_Washington_Coursera |
Now we will write a function that will accept an SFrame, a list of feature names (e.g. ['sqft_living', 'bedrooms']) and an target feature e.g. ('price') and will return two things:* A numpy matrix whose columns are the desired features plus a constant column (this is how we create an 'intercept')* A numpy array containing the values of the outputWith this in mind, complete the following function (where there's an empty line you should write a line of code that does what the comment above indicates)**Please note you will need GraphLab Create version at least 1.7.1 in order for .to_numpy() to work!** | def get_numpy_data(data_sframe, features, output):
data_sframe['constant'] = 1 # this is how you add a constant column to an SFrame
# add the column 'constant' to the front of the features list so that we can extract it along with the others:
features = ['constant'] + features # this is how you combine two lists
# select the columns of data_SFrame given by the features list into the SFrame features_sframe (now including constant):
# the following line will convert the features_SFrame into a numpy matrix:
feature_matrix = features_sframe.to_numpy()
# assign the column of data_sframe associated with the output to the SArray output_sarray
# the following will convert the SArray into a numpy array by first converting it to a list
output_array = output_sarray.to_numpy()
return(feature_matrix, output_array) | _____no_output_____ | MIT | Machine_Learning_Regression/.ipynb_checkpoints/week-2-multiple-regression-assignment-2-blank-checkpoint.ipynb | nkmah2/ML_Uni_Washington_Coursera |
For testing let's use the 'sqft_living' feature and a constant as our features and price as our output: | (example_features, example_output) = get_numpy_data(sales, ['sqft_living'], 'price') # the [] around 'sqft_living' makes it a list
print example_features[0,:] # this accesses the first row of the data the ':' indicates 'all columns'
print example_output[0] # and the corresponding output | _____no_output_____ | MIT | Machine_Learning_Regression/.ipynb_checkpoints/week-2-multiple-regression-assignment-2-blank-checkpoint.ipynb | nkmah2/ML_Uni_Washington_Coursera |
Predicting output given regression weights Suppose we had the weights [1.0, 1.0] and the features [1.0, 1180.0] and we wanted to compute the predicted output 1.0\*1.0 + 1.0\*1180.0 = 1181.0 this is the dot product between these two arrays. If they're numpy arrayws we can use np.dot() to compute this: | my_weights = np.array([1., 1.]) # the example weights
my_features = example_features[0,] # we'll use the first data point
predicted_value = np.dot(my_features, my_weights)
print predicted_value | _____no_output_____ | MIT | Machine_Learning_Regression/.ipynb_checkpoints/week-2-multiple-regression-assignment-2-blank-checkpoint.ipynb | nkmah2/ML_Uni_Washington_Coursera |
np.dot() also works when dealing with a matrix and a vector. Recall that the predictions from all the observations is just the RIGHT (as in weights on the right) dot product between the features *matrix* and the weights *vector*. With this in mind finish the following predict_output function to compute the predictions for an entire matrix of features given the matrix and the weights: | def predict_output(feature_matrix, weights):
# assume feature_matrix is a numpy matrix containing the features as columns and weights is a corresponding numpy array
# create the predictions vector by using np.dot()
return(predictions) | _____no_output_____ | MIT | Machine_Learning_Regression/.ipynb_checkpoints/week-2-multiple-regression-assignment-2-blank-checkpoint.ipynb | nkmah2/ML_Uni_Washington_Coursera |
If you want to test your code run the following cell: | test_predictions = predict_output(example_features, my_weights)
print test_predictions[0] # should be 1181.0
print test_predictions[1] # should be 2571.0 | _____no_output_____ | MIT | Machine_Learning_Regression/.ipynb_checkpoints/week-2-multiple-regression-assignment-2-blank-checkpoint.ipynb | nkmah2/ML_Uni_Washington_Coursera |
Computing the Derivative We are now going to move to computing the derivative of the regression cost function. Recall that the cost function is the sum over the data points of the squared difference between an observed output and a predicted output.Since the derivative of a sum is the sum of the derivatives we can compute the derivative for a single data point and then sum over data points. We can write the squared difference between the observed output and predicted output for a single point as follows:(w[0]\*[CONSTANT] + w[1]\*[feature_1] + ... + w[i] \*[feature_i] + ... + w[k]\*[feature_k] - output)^2Where we have k features and a constant. So the derivative with respect to weight w[i] by the chain rule is:2\*(w[0]\*[CONSTANT] + w[1]\*[feature_1] + ... + w[i] \*[feature_i] + ... + w[k]\*[feature_k] - output)\* [feature_i]The term inside the paranethesis is just the error (difference between prediction and output). So we can re-write this as:2\*error\*[feature_i]That is, the derivative for the weight for feature i is the sum (over data points) of 2 times the product of the error and the feature itself. In the case of the constant then this is just twice the sum of the errors!Recall that twice the sum of the product of two vectors is just twice the dot product of the two vectors. Therefore the derivative for the weight for feature_i is just two times the dot product between the values of feature_i and the current errors. With this in mind complete the following derivative function which computes the derivative of the weight given the value of the feature (over all data points) and the errors (over all data points). | def feature_derivative(errors, feature):
# Assume that errors and feature are both numpy arrays of the same length (number of data points)
# compute twice the dot product of these vectors as 'derivative' and return the value
return(derivative) | _____no_output_____ | MIT | Machine_Learning_Regression/.ipynb_checkpoints/week-2-multiple-regression-assignment-2-blank-checkpoint.ipynb | nkmah2/ML_Uni_Washington_Coursera |
To test your feature derivartive run the following: | (example_features, example_output) = get_numpy_data(sales, ['sqft_living'], 'price')
my_weights = np.array([0., 0.]) # this makes all the predictions 0
test_predictions = predict_output(example_features, my_weights)
# just like SFrames 2 numpy arrays can be elementwise subtracted with '-':
errors = test_predictions - example_output # prediction errors in this case is just the -example_output
feature = example_features[:,0] # let's compute the derivative with respect to 'constant', the ":" indicates "all rows"
derivative = feature_derivative(errors, feature)
print derivative
print -np.sum(example_output)*2 # should be the same as derivative | _____no_output_____ | MIT | Machine_Learning_Regression/.ipynb_checkpoints/week-2-multiple-regression-assignment-2-blank-checkpoint.ipynb | nkmah2/ML_Uni_Washington_Coursera |
Gradient Descent Now we will write a function that performs a gradient descent. The basic premise is simple. Given a starting point we update the current weights by moving in the negative gradient direction. Recall that the gradient is the direction of *increase* and therefore the negative gradient is the direction of *decrease* and we're trying to *minimize* a cost function. The amount by which we move in the negative gradient *direction* is called the 'step size'. We stop when we are 'sufficiently close' to the optimum. We define this by requiring that the magnitude (length) of the gradient vector to be smaller than a fixed 'tolerance'.With this in mind, complete the following gradient descent function below using your derivative function above. For each step in the gradient descent we update the weight for each feature befofe computing our stopping criteria | from math import sqrt # recall that the magnitude/length of a vector [g[0], g[1], g[2]] is sqrt(g[0]^2 + g[1]^2 + g[2]^2)
def regression_gradient_descent(feature_matrix, output, initial_weights, step_size, tolerance):
converged = False
weights = np.array(initial_weights) # make sure it's a numpy array
while not converged:
# compute the predictions based on feature_matrix and weights using your predict_output() function
# compute the errors as predictions - output
gradient_sum_squares = 0 # initialize the gradient sum of squares
# while we haven't reached the tolerance yet, update each feature's weight
for i in range(len(weights)): # loop over each weight
# Recall that feature_matrix[:, i] is the feature column associated with weights[i]
# compute the derivative for weight[i]:
# add the squared value of the derivative to the gradient magnitude (for assessing convergence)
# subtract the step size times the derivative from the current weight
# compute the square-root of the gradient sum of squares to get the gradient matnigude:
gradient_magnitude = sqrt(gradient_sum_squares)
if gradient_magnitude < tolerance:
converged = True
return(weights) | _____no_output_____ | MIT | Machine_Learning_Regression/.ipynb_checkpoints/week-2-multiple-regression-assignment-2-blank-checkpoint.ipynb | nkmah2/ML_Uni_Washington_Coursera |
A few things to note before we run the gradient descent. Since the gradient is a sum over all the data points and involves a product of an error and a feature the gradient itself will be very large since the features are large (squarefeet) and the output is large (prices). So while you might expect "tolerance" to be small, small is only relative to the size of the features. For similar reasons the step size will be much smaller than you might expect but this is because the gradient has such large values. Running the Gradient Descent as Simple Regression First let's split the data into training and test data. | train_data,test_data = sales.random_split(.8,seed=0) | _____no_output_____ | MIT | Machine_Learning_Regression/.ipynb_checkpoints/week-2-multiple-regression-assignment-2-blank-checkpoint.ipynb | nkmah2/ML_Uni_Washington_Coursera |
Although the gradient descent is designed for multiple regression since the constant is now a feature we can use the gradient descent function to estimat the parameters in the simple regression on squarefeet. The folowing cell sets up the feature_matrix, output, initial weights and step size for the first model: | # let's test out the gradient descent
simple_features = ['sqft_living']
my_output = 'price'
(simple_feature_matrix, output) = get_numpy_data(train_data, simple_features, my_output)
initial_weights = np.array([-47000., 1.])
step_size = 7e-12
tolerance = 2.5e7 | _____no_output_____ | MIT | Machine_Learning_Regression/.ipynb_checkpoints/week-2-multiple-regression-assignment-2-blank-checkpoint.ipynb | nkmah2/ML_Uni_Washington_Coursera |
Next run your gradient descent with the above parameters. How do your weights compare to those achieved in week 1 (don't expect them to be exactly the same)? **Quiz Question: What is the value of the weight for sqft_living -- the second element of ‘simple_weights’ (rounded to 1 decimal place)?** Use your newly estimated weights and your predict_output() function to compute the predictions on all the TEST data (you will need to create a numpy array of the test feature_matrix and test output first: | (test_simple_feature_matrix, test_output) = get_numpy_data(test_data, simple_features, my_output) | _____no_output_____ | MIT | Machine_Learning_Regression/.ipynb_checkpoints/week-2-multiple-regression-assignment-2-blank-checkpoint.ipynb | nkmah2/ML_Uni_Washington_Coursera |
Now compute your predictions using test_simple_feature_matrix and your weights from above. **Quiz Question: What is the predicted price for the 1st house in the TEST data set for model 1 (round to nearest dollar)?** Now that you have the predictions on test data, compute the RSS on the test data set. Save this value for comparison later. Recall that RSS is the sum of the squared errors (difference between prediction and output). Running a multiple regression Now we will use more than one actual feature. Use the following code to produce the weights for a second model with the following parameters: | model_features = ['sqft_living', 'sqft_living15'] # sqft_living15 is the average squarefeet for the nearest 15 neighbors.
my_output = 'price'
(feature_matrix, output) = get_numpy_data(train_data, model_features, my_output)
initial_weights = np.array([-100000., 1., 1.])
step_size = 4e-12
tolerance = 1e9 | _____no_output_____ | MIT | Machine_Learning_Regression/.ipynb_checkpoints/week-2-multiple-regression-assignment-2-blank-checkpoint.ipynb | nkmah2/ML_Uni_Washington_Coursera |
Data can be found: https://data-seattlecitygis.opendata.arcgis.com/search?collection=Dataset&modified=2021-01-01%2C2021-10-13 | import geopandas as gpd
gpd.datasets.available
world = gpd.read_file(
gpd.datasets.get_path('naturalearth_lowres')
)
seattle_zoning_2035 = gpd.read_file('Future_Land_Use__2035.shp')
seattle_zoning_2035.head()
education_centers = gpd.read_file('data/Environmental_Education_Centers.shp')
education_centers | _____no_output_____ | Apache-2.0 | _notebooks/public_schools/EDA.ipynb | Hevia/blog |
Advanced Logistic Regression in TensorFlow 2.0 Learning Objectives1. Load a CSV file using Pandas2. Create train, validation, and test sets3. Define and train a model using Keras (including setting class weights)4. Evaluate the model using various metrics (including precision and recall)5. Try common techniques for dealing with imbalanced data: Class weighting and Oversampling Introduction This lab how to classify a highly imbalanced dataset in which the number of examples in one class greatly outnumbers the examples in another. You will work with the [Credit Card Fraud Detection](https://www.kaggle.com/mlg-ulb/creditcardfraud) dataset hosted on Kaggle. The aim is to detect a mere 492 fraudulent transactions from 284,807 transactions in total. You will use [Keras](../../guide/keras/overview.ipynb) to define the model and [class weights](https://www.tensorflow.org/versions/r2.0/api_docs/python/tf/keras/Model) to help the model learn from the imbalanced data. PENDING LINK UPDATE: Each learning objective will correspond to a __TODO__ in the [student lab notebook](https://training-data-analyst/courses/machine_learning/deepdive2/image_classification/labs/5_fashion_mnist_class.ipynb) -- try to complete that notebook first before reviewing this solution notebook. Start by importing the necessary libraries for this lab. | import tensorflow as tf
from tensorflow import keras
import os
import tempfile
import matplotlib as mpl
import matplotlib.pyplot as plt
import numpy as np
import pandas as pd
import seaborn as sns
import sklearn
from sklearn.metrics import confusion_matrix
from sklearn.model_selection import train_test_split
from sklearn.preprocessing import StandardScaler
print("TensorFlow version: ",tf.version.VERSION) | TensorFlow version: 2.1.0
| Apache-2.0 | courses/machine_learning/deepdive2/introduction_to_tensorflow/solutions/adv_logistic_reg_TF2.0.ipynb | Best-Cloud-Practice-for-Data-Science/training-data-analyst |
In the next cell, we're going to customize our Matplot lib visualization figure size and colors. Note that each time Matplotlib loads, it defines a runtime configuration (rc) containing the default styles for every plot element we create. This configuration can be adjusted at any time using the plt.rc convenience routine. | mpl.rcParams['figure.figsize'] = (12, 10)
colors = plt.rcParams['axes.prop_cycle'].by_key()['color'] | _____no_output_____ | Apache-2.0 | courses/machine_learning/deepdive2/introduction_to_tensorflow/solutions/adv_logistic_reg_TF2.0.ipynb | Best-Cloud-Practice-for-Data-Science/training-data-analyst |
Data processing and exploration Download the Kaggle Credit Card Fraud data setPandas is a Python library with many helpful utilities for loading and working with structured data and can be used to download CSVs into a dataframe.Note: This dataset has been collected and analysed during a research collaboration of Worldline and the [Machine Learning Group](http://mlg.ulb.ac.be) of ULB (Université Libre de Bruxelles) on big data mining and fraud detection. More details on current and past projects on related topics are available [here](https://www.researchgate.net/project/Fraud-detection-5) and the page of the [DefeatFraud](https://mlg.ulb.ac.be/wordpress/portfolio_page/defeatfraud-assessment-and-validation-of-deep-feature-engineering-and-learning-solutions-for-fraud-detection/) project | file = tf.keras.utils
raw_df = pd.read_csv('https://storage.googleapis.com/download.tensorflow.org/data/creditcard.csv')
raw_df.head() | _____no_output_____ | Apache-2.0 | courses/machine_learning/deepdive2/introduction_to_tensorflow/solutions/adv_logistic_reg_TF2.0.ipynb | Best-Cloud-Practice-for-Data-Science/training-data-analyst |
Now, let's view the statistics of the raw dataframe. | raw_df[['Time', 'V1', 'V2', 'V3', 'V4', 'V5', 'V26', 'V27', 'V28', 'Amount', 'Class']].describe() | _____no_output_____ | Apache-2.0 | courses/machine_learning/deepdive2/introduction_to_tensorflow/solutions/adv_logistic_reg_TF2.0.ipynb | Best-Cloud-Practice-for-Data-Science/training-data-analyst |
Examine the class label imbalanceLet's look at the dataset imbalance: | neg, pos = np.bincount(raw_df['Class'])
total = neg + pos
print('Examples:\n Total: {}\n Positive: {} ({:.2f}% of total)\n'.format(
total, pos, 100 * pos / total)) | Examples:
Total: 284807
Positive: 492 (0.17% of total)
| Apache-2.0 | courses/machine_learning/deepdive2/introduction_to_tensorflow/solutions/adv_logistic_reg_TF2.0.ipynb | Best-Cloud-Practice-for-Data-Science/training-data-analyst |
This shows the small fraction of positive samples. Clean, split and normalize the dataThe raw data has a few issues. First the `Time` and `Amount` columns are too variable to use directly. Drop the `Time` column (since it's not clear what it means) and take the log of the `Amount` column to reduce its range. | cleaned_df = raw_df.copy()
# You don't want the `Time` column.
cleaned_df.pop('Time')
# The `Amount` column covers a huge range. Convert to log-space.
eps=0.001 # 0 => 0.1¢
cleaned_df['Log Ammount'] = np.log(cleaned_df.pop('Amount')+eps) | _____no_output_____ | Apache-2.0 | courses/machine_learning/deepdive2/introduction_to_tensorflow/solutions/adv_logistic_reg_TF2.0.ipynb | Best-Cloud-Practice-for-Data-Science/training-data-analyst |
Split the dataset into train, validation, and test sets. The validation set is used during the model fitting to evaluate the loss and any metrics, however the model is not fit with this data. The test set is completely unused during the training phase and is only used at the end to evaluate how well the model generalizes to new data. This is especially important with imbalanced datasets where [overfitting](https://developers.google.com/machine-learning/crash-course/generalization/peril-of-overfitting) is a significant concern from the lack of training data. | # Use a utility from sklearn to split and shuffle our dataset.
train_df, test_df = train_test_split(cleaned_df, test_size=0.2)
train_df, val_df = train_test_split(train_df, test_size=0.2)
# Form np arrays of labels and features.
train_labels = np.array(train_df.pop('Class'))
bool_train_labels = train_labels != 0
val_labels = np.array(val_df.pop('Class'))
test_labels = np.array(test_df.pop('Class'))
train_features = np.array(train_df)
val_features = np.array(val_df)
test_features = np.array(test_df) | _____no_output_____ | Apache-2.0 | courses/machine_learning/deepdive2/introduction_to_tensorflow/solutions/adv_logistic_reg_TF2.0.ipynb | Best-Cloud-Practice-for-Data-Science/training-data-analyst |
Normalize the input features using the sklearn StandardScaler.This will set the mean to 0 and standard deviation to 1.Note: The `StandardScaler` is only fit using the `train_features` to be sure the model is not peeking at the validation or test sets. | scaler = StandardScaler()
train_features = scaler.fit_transform(train_features)
val_features = scaler.transform(val_features)
test_features = scaler.transform(test_features)
train_features = np.clip(train_features, -5, 5)
val_features = np.clip(val_features, -5, 5)
test_features = np.clip(test_features, -5, 5)
print('Training labels shape:', train_labels.shape)
print('Validation labels shape:', val_labels.shape)
print('Test labels shape:', test_labels.shape)
print('Training features shape:', train_features.shape)
print('Validation features shape:', val_features.shape)
print('Test features shape:', test_features.shape)
| Training labels shape: (182276,)
Validation labels shape: (45569,)
Test labels shape: (56962,)
Training features shape: (182276, 29)
Validation features shape: (45569, 29)
Test features shape: (56962, 29)
| Apache-2.0 | courses/machine_learning/deepdive2/introduction_to_tensorflow/solutions/adv_logistic_reg_TF2.0.ipynb | Best-Cloud-Practice-for-Data-Science/training-data-analyst |
Caution: If you want to deploy a model, it's critical that you preserve the preprocessing calculations. The easiest way to implement them as layers, and attach them to your model before export. Look at the data distributionNext compare the distributions of the positive and negative examples over a few features. Good questions to ask yourself at this point are:* Do these distributions make sense? * Yes. You've normalized the input and these are mostly concentrated in the `+/- 2` range.* Can you see the difference between the ditributions? * Yes the positive examples contain a much higher rate of extreme values. | pos_df = pd.DataFrame(train_features[ bool_train_labels], columns = train_df.columns)
neg_df = pd.DataFrame(train_features[~bool_train_labels], columns = train_df.columns)
sns.jointplot(pos_df['V5'], pos_df['V6'],
kind='hex', xlim = (-5,5), ylim = (-5,5))
plt.suptitle("Positive distribution")
sns.jointplot(neg_df['V5'], neg_df['V6'],
kind='hex', xlim = (-5,5), ylim = (-5,5))
_ = plt.suptitle("Negative distribution") | _____no_output_____ | Apache-2.0 | courses/machine_learning/deepdive2/introduction_to_tensorflow/solutions/adv_logistic_reg_TF2.0.ipynb | Best-Cloud-Practice-for-Data-Science/training-data-analyst |
Define the model and metricsDefine a function that creates a simple neural network with a densly connected hidden layer, a [dropout](https://developers.google.com/machine-learning/glossary/dropout_regularization) layer to reduce overfitting, and an output sigmoid layer that returns the probability of a transaction being fraudulent: | METRICS = [
keras.metrics.TruePositives(name='tp'),
keras.metrics.FalsePositives(name='fp'),
keras.metrics.TrueNegatives(name='tn'),
keras.metrics.FalseNegatives(name='fn'),
keras.metrics.BinaryAccuracy(name='accuracy'),
keras.metrics.Precision(name='precision'),
keras.metrics.Recall(name='recall'),
keras.metrics.AUC(name='auc'),
]
def make_model(metrics = METRICS, output_bias=None):
if output_bias is not None:
output_bias = tf.keras.initializers.Constant(output_bias)
model = keras.Sequential([
keras.layers.Dense(
16, activation='relu',
input_shape=(train_features.shape[-1],)),
keras.layers.Dropout(0.5),
keras.layers.Dense(1, activation='sigmoid',
bias_initializer=output_bias),
])
model.compile(
optimizer=keras.optimizers.Adam(lr=1e-3),
loss=keras.losses.BinaryCrossentropy(),
metrics=metrics)
return model | _____no_output_____ | Apache-2.0 | courses/machine_learning/deepdive2/introduction_to_tensorflow/solutions/adv_logistic_reg_TF2.0.ipynb | Best-Cloud-Practice-for-Data-Science/training-data-analyst |
Understanding useful metricsNotice that there are a few metrics defined above that can be computed by the model that will be helpful when evaluating the performance.* **False** negatives and **false** positives are samples that were **incorrectly** classified* **True** negatives and **true** positives are samples that were **correctly** classified* **Accuracy** is the percentage of examples correctly classified> $\frac{\text{true samples}}{\text{total samples}}$* **Precision** is the percentage of **predicted** positives that were correctly classified> $\frac{\text{true positives}}{\text{true positives + false positives}}$* **Recall** is the percentage of **actual** positives that were correctly classified> $\frac{\text{true positives}}{\text{true positives + false negatives}}$* **AUC** refers to the Area Under the Curve of a Receiver Operating Characteristic curve (ROC-AUC). This metric is equal to the probability that a classifier will rank a random positive sample higher than than a random negative sample.Note: Accuracy is not a helpful metric for this task. You can 99.8%+ accuracy on this task by predicting False all the time. Read more:* [True vs. False and Positive vs. Negative](https://developers.google.com/machine-learning/crash-course/classification/true-false-positive-negative)* [Accuracy](https://developers.google.com/machine-learning/crash-course/classification/accuracy)* [Precision and Recall](https://developers.google.com/machine-learning/crash-course/classification/precision-and-recall)* [ROC-AUC](https://developers.google.com/machine-learning/crash-course/classification/roc-and-auc) Baseline model Build the modelNow create and train your model using the function that was defined earlier. Notice that the model is fit using a larger than default batch size of 2048, this is important to ensure that each batch has a decent chance of containing a few positive samples. If the batch size was too small, they would likely have no fraudulent transactions to learn from.Note: this model will not handle the class imbalance well. You will improve it later in this tutorial. | EPOCHS = 100
BATCH_SIZE = 2048
early_stopping = tf.keras.callbacks.EarlyStopping(
monitor='val_auc',
verbose=1,
patience=10,
mode='max',
restore_best_weights=True)
model = make_model()
model.summary() | Model: "sequential_8"
_________________________________________________________________
Layer (type) Output Shape Param #
=================================================================
dense_16 (Dense) (None, 16) 480
_________________________________________________________________
dropout_8 (Dropout) (None, 16) 0
_________________________________________________________________
dense_17 (Dense) (None, 1) 17
=================================================================
Total params: 497
Trainable params: 497
Non-trainable params: 0
_________________________________________________________________
| Apache-2.0 | courses/machine_learning/deepdive2/introduction_to_tensorflow/solutions/adv_logistic_reg_TF2.0.ipynb | Best-Cloud-Practice-for-Data-Science/training-data-analyst |
Test run the model: | model.predict(train_features[:10]) | _____no_output_____ | Apache-2.0 | courses/machine_learning/deepdive2/introduction_to_tensorflow/solutions/adv_logistic_reg_TF2.0.ipynb | Best-Cloud-Practice-for-Data-Science/training-data-analyst |
Optional: Set the correct initial bias. These are initial guesses are not great. You know the dataset is imbalanced. Set the output layer's bias to reflect that (See: [A Recipe for Training Neural Networks: "init well"](http://karpathy.github.io/2019/04/25/recipe/2-set-up-the-end-to-end-trainingevaluation-skeleton--get-dumb-baselines)). This can help with initial convergence. With the default bias initialization the loss should be about `math.log(2) = 0.69314` | results = model.evaluate(train_features, train_labels, batch_size=BATCH_SIZE, verbose=0)
print("Loss: {:0.4f}".format(results[0])) | Loss: 1.7441
| Apache-2.0 | courses/machine_learning/deepdive2/introduction_to_tensorflow/solutions/adv_logistic_reg_TF2.0.ipynb | Best-Cloud-Practice-for-Data-Science/training-data-analyst |
The correct bias to set can be derived from:$$ p_0 = pos/(pos + neg) = 1/(1+e^{-b_0}) $$$$ b_0 = -log_e(1/p_0 - 1) $$$$ b_0 = log_e(pos/neg)$$ | initial_bias = np.log([pos/neg])
initial_bias | _____no_output_____ | Apache-2.0 | courses/machine_learning/deepdive2/introduction_to_tensorflow/solutions/adv_logistic_reg_TF2.0.ipynb | Best-Cloud-Practice-for-Data-Science/training-data-analyst |
Set that as the initial bias, and the model will give much more reasonable initial guesses. It should be near: `pos/total = 0.0018` | model = make_model(output_bias = initial_bias)
model.predict(train_features[:10]) | _____no_output_____ | Apache-2.0 | courses/machine_learning/deepdive2/introduction_to_tensorflow/solutions/adv_logistic_reg_TF2.0.ipynb | Best-Cloud-Practice-for-Data-Science/training-data-analyst |
With this initialization the initial loss should be approximately:$$-p_0log(p_0)-(1-p_0)log(1-p_0) = 0.01317$$ | results = model.evaluate(train_features, train_labels, batch_size=BATCH_SIZE, verbose=0)
print("Loss: {:0.4f}".format(results[0])) | Loss: 0.0275
| Apache-2.0 | courses/machine_learning/deepdive2/introduction_to_tensorflow/solutions/adv_logistic_reg_TF2.0.ipynb | Best-Cloud-Practice-for-Data-Science/training-data-analyst |
This initial loss is about 50 times less than if would have been with naive initilization.This way the model doesn't need to spend the first few epochs just learning that positive examples are unlikely. This also makes it easier to read plots of the loss during training. Checkpoint the initial weightsTo make the various training runs more comparable, keep this initial model's weights in a checkpoint file, and load them into each model before training. | initial_weights = os.path.join(tempfile.mkdtemp(),'initial_weights')
model.save_weights(initial_weights) | _____no_output_____ | Apache-2.0 | courses/machine_learning/deepdive2/introduction_to_tensorflow/solutions/adv_logistic_reg_TF2.0.ipynb | Best-Cloud-Practice-for-Data-Science/training-data-analyst |
Confirm that the bias fix helpsBefore moving on, confirm quick that the careful bias initialization actually helped.Train the model for 20 epochs, with and without this careful initialization, and compare the losses: | model = make_model()
model.load_weights(initial_weights)
model.layers[-1].bias.assign([0.0])
zero_bias_history = model.fit(
train_features,
train_labels,
batch_size=BATCH_SIZE,
epochs=20,
validation_data=(val_features, val_labels),
verbose=0)
model = make_model()
model.load_weights(initial_weights)
careful_bias_history = model.fit(
train_features,
train_labels,
batch_size=BATCH_SIZE,
epochs=20,
validation_data=(val_features, val_labels),
verbose=0)
def plot_loss(history, label, n):
# Use a log scale to show the wide range of values.
plt.semilogy(history.epoch, history.history['loss'],
color=colors[n], label='Train '+label)
plt.semilogy(history.epoch, history.history['val_loss'],
color=colors[n], label='Val '+label,
linestyle="--")
plt.xlabel('Epoch')
plt.ylabel('Loss')
plt.legend()
plot_loss(zero_bias_history, "Zero Bias", 0)
plot_loss(careful_bias_history, "Careful Bias", 1) | _____no_output_____ | Apache-2.0 | courses/machine_learning/deepdive2/introduction_to_tensorflow/solutions/adv_logistic_reg_TF2.0.ipynb | Best-Cloud-Practice-for-Data-Science/training-data-analyst |
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