update app.py

app.py

@@ -5,7 +5,6 @@ import os
 import pandas as pd
 import geopandas as gpd
 from datetime import datetime
-from shapely.geometry import Point
 import leafmap.foliumap as leafmap
 
 # Set up the page layout
@@ -53,6 +52,9 @@ st.header("Earth Engine Index Calculator")
 # Choose Index or Custom Formula
 index_choice = st.selectbox("Select an Index or Enter Custom Formula", ['NDVI', 'NDWI', 'Average NO₂', 'Custom Formula'])
 
+# Initialize custom_formula variable
+custom_formula = ""
+
 # Display corresponding formula based on the index selected
 if index_choice == 'NDVI':
     st.write("Formula for NDVI: NDVI = (B8 - B4) / (B8 + B4)")
@@ -60,13 +62,9 @@ elif index_choice == 'NDWI':
     st.write("Formula for NDWI: NDWI = (B3 - B8) / (B3 + B8)")
 elif index_choice == 'Average NO₂':
     st.write("Formula for Average NO₂: Average NO₂ = Mean(NO2 band)")
-elif index_choice == 'Custom Formula' and custom_formula:
-    st.write(f"Custom Formula: {custom_formula}")
-
-# Enter custom formula if selected
-custom_formula = ""
-if index_choice == 'Custom Formula':
+elif index_choice == 'Custom Formula':
     custom_formula = st.text_input("Enter Custom Formula (e.g., 'B5 - B4 / B5 + B4')")
+    st.write(f"Custom Formula: {custom_formula}")  # Display the custom formula after the user inputs it
 
 # Function to read points from CSV
 def read_csv(file_path):
@@ -280,12 +278,11 @@ if file_upload:
     if st.session_state.results:
         # Convert the results to a DataFrame for better visualization
         result_df = pd.DataFrame(st.session_state.results)
-        
+    
         # Show the results in a table format
         st.write("Processed Results Table:")
-        st.dataframe(result_df)  
+        st.dataframe(result_df)
 
-        # Allow user to download results as CSV
         st.download_button(
             label="Download results as CSV",
             data=result_df.to_csv(index=False).encode('utf-8'),