Row Similarity

The spark version of itemsimilarity only has LLR as a metric. But what about RSJ? it’s a pretty simple thing to convert itemsimilarity to rowsimilarity but RSJ has some uses beyond collaborative filtering. Are some of the other similarity metrics needed?

Specifically text comparison typically weights the terms in the DRM with TF-IDF. Then a user would apply SIMILARITY_COSINE or SIMILARITY_TANIMOTO. Then again I’ve seen some using LLR for this too.

Are some of the other similarity metrics needed for RSJ?