Add one or more submatrices to a sparse score matrix
fill_in_sparse_score_mat(sparse_matrix, ..., diag = NULL)either an existing (square) sparse matrix or a character vector of names that will be used to define an empty sparse matrix.
Additional matrices to insert into sparse_matrix. Row and
column names must have matches in sparse_matrix.
optional full diagonal for sparse matrix i.e. self-match scores.
sparse_score_mat