backend/inference.py

import pandas as pd
import jax.numpy as jnp

from typing import List, Union

# Defining cosine similarity using flax.
from backend.config import MODELS_ID
from backend.utils import load_model


def cos_sim(a, b):
    return jnp.matmul(a, jnp.transpose(b)) / (jnp.linalg.norm(a) * jnp.linalg.norm(b))


# We get similarity between embeddings.
def text_similarity(anchor: str, inputs: List[str], model_name: str, model_dict: dict):
    print(model_name)
    model = load_model(model_name, model_dict)

    # Creating embeddings
    if hasattr(model, 'encode'):
        anchor_emb = model.encode(anchor)[None, :]
        inputs_emb = model.encode(inputs)
    else:
        assert len(model) == 2
        anchor_emb = model[0].encode(anchor)[None, :]
        inputs_emb = model[1].encode(inputs)

    # Obtaining similarity
    similarity = list(jnp.squeeze(cos_sim(anchor_emb, inputs_emb)))

    # Returning a Pandas' dataframe
    d = {'inputs': inputs,
         'score': [round(similarity[i], 3) for i in range(len(similarity))]}
    df = pd.DataFrame(d, columns=['inputs', 'score'])

    return df