Retuen the number of non-zero values of the specified submatrix of a given sparse matrix rapidly
nnzero(m, rows = 1:dim(m)[1], cols = 1:dim(m)[2])
The matrix
The integer vector of row index(es) or logical vector indicated the selected rows
The integer vector of column index(es) or logical vector indicated the selected cols
This function will return the number of non-zero values in the specified submatrix.
This function implements faster calculation algorithm for the
CsparseMatrix
and RsparseMatrix
class in the package Matrix.