DocArrayInMemorySearch -> similarity_search_with_score returns incorrect results with Ollama

[anatoli26]

Hi, thanks for your videos and the code.

I'm trying to advance with your 2 vids for this repo and the youtube-rag one.

For some reason I can't make the DocArrayInMemorySearch work correctly with the basic example. Here's the simplified code merged from both repos:

import os
from dotenv import load_dotenv
from langchain_community.vectorstores import DocArrayInMemorySearch
from langchain_community.embeddings import OllamaEmbeddings
from langchain_community.llms import Ollama

load_dotenv()

# Initialize Ollama embeddings
MODEL = "llama3"
model = Ollama(model=MODEL)
embeddings = OllamaEmbeddings(model=MODEL)

# Create a list of documents
vectorstore1 = DocArrayInMemorySearch.from_texts(
    [
        "Mary's sister is Susana",
        "John and Tommy are brothers",
        "Patricia likes white cars",
        "Pedro's mother is a teacher",
        "Lucia drives an Audi",
        "Mary has two siblings",
    ],
    embedding=embeddings,
)

print(vectorstore1.similarity_search_with_score(query="Who is Mary's sister?", k=6))

The results are as follows (split with new lines for easier reading):

[
    (Document(page_content="Pedro's mother is a teacher"), 0.4350104103848039),
    (Document(page_content='Mary has two siblings'), 0.43119987668775467),
    (Document(page_content='John and Tommy are brothers'), 0.41273142441302735),
    (Document(page_content='Patricia likes white cars'), 0.3569403395446856),
    (Document(page_content="Mary's sister is Susana"), 0.3464697744599006),
    (Document(page_content='Lucia drives an Audi'), 0.22815817605634237)
]

Why the similarity score and the order don't match what is shown in your videos and the notebooks? I.e. (Document(page_content="Mary's sister is Susana"), 0.3464697744599006) is the 5th result when it should be the first one.

I'm using python 3.10.12.

Thanks!