Computes the cosine similarity matrix from the gene signature matrix of a
cellMarkers object or any matrix. Note that this function computes cosine
similarity between matrix columns, unlike dist() which computes the
distance metric between matrix rows.
cos_similarity(x, use_filter = NULL)A symmetric similarity matrix.
Either a matrix or a 'cellMarkers' class or 'deconv' class object.
Logical whether to use filtered gene signature.