Cosine similarity in r

1. Does cosine similarity use TF IDF?
2. What is cosine similarity in Knn?
3. Is cosine similarity the same as Pearson correlation?

Does cosine similarity use TF IDF?

Yes, tfidf is just one of many ways to compute a (non-negative) feature vector for a text document, and Cosine Similarity is just one of several ways to compare feature vectors for similarity.

What is cosine similarity in Knn?

Cosine similarity is used as a metric in different machine learning algorithms like the KNN for determining the distance between the neighbors, in recommendation systems, it is used to recommend movies with the same similarities and for textual data, it is used to find the similarity of texts in the document.

Is cosine similarity the same as Pearson correlation?

The cosine similarity computes the similarity between two samples, whereas the Pearson correlation coefficient computes the correlation between two jointly distributed random variables.