model change

app.py

@@ -20,14 +20,14 @@ def loading_pdf():
 def pdf_changes(pdf_doc):
     loader = OnlinePDFLoader(pdf_doc.name)
     documents = loader.load()
-    text_splitter = CharacterTextSplitter(chunk_size=500, chunk_overlap=50)
+    text_splitter = CharacterTextSplitter(chunk_size=1000, chunk_overlap=100)
     texts = text_splitter.split_documents(documents)
     embeddings = OpenAIEmbeddings()
     db = Chroma.from_documents(texts, embeddings)
     retriever = db.as_retriever()
     global qa 
     qa = ConversationalRetrievalChain.from_llm(
-        llm=OpenAI(temperature=0.5),  
+        llm=OpenAI(temperature=0.2, engine=GPT3-turbo, max_tokens=16000),  
         retriever=retriever, 
         return_source_documents=False)
     return "Ready"