Source code for langchain.retrievers.svm
"""SMV Retriever.
Largely based on
https://github.com/karpathy/randomfun/blob/master/knn_vs_svm.ipynb"""
from __future__ import annotations
import concurrent.futures
from typing import Any, List, Optional
import numpy as np
from pydantic import BaseModel
from langchain.embeddings.base import Embeddings
from langchain.schema import BaseRetriever, Document
def create_index(contexts: List[str], embeddings: Embeddings) -> np.ndarray:
    with concurrent.futures.ThreadPoolExecutor() as executor:
        return np.array(list(executor.map(embeddings.embed_query, contexts)))
[docs]class SVMRetriever(BaseRetriever, BaseModel):
    embeddings: Embeddings
    index: Any
    texts: List[str]
    k: int = 4
    relevancy_threshold: Optional[float] = None
    class Config:
        """Configuration for this pydantic object."""
        arbitrary_types_allowed = True
[docs]    @classmethod
    def from_texts(
        cls, texts: List[str], embeddings: Embeddings, **kwargs: Any
    ) -> SVMRetriever:
        index = create_index(texts, embeddings)
        return cls(embeddings=embeddings, index=index, texts=texts, **kwargs)
[docs]    def get_relevant_documents(self, query: str) -> List[Document]:
        from sklearn import svm
        query_embeds = np.array(self.embeddings.embed_query(query))
        x = np.concatenate([query_embeds[None, ...], self.index])
        y = np.zeros(x.shape[0])
        y[0] = 1
        clf = svm.LinearSVC(
rtdocs_stable/api.python.langchain.com/en/stable/_modules/langchain/retrievers/svm.html