If your program uses a sparse matrix stored by rows, as defined in Storage-by-Rows, you should first convert your sparse matrix to compressed-matrix storage mode by using the subroutine DSRSM on page DSRSM--Convert a Sparse Matrix from Storage-by-Rows to Compressed-Matrix Storage Mode. DSRSM converts a matrix to compressed-matrix storage mode. To convert your sparse matrix to compressed-diagonal storage mode, you need to perform this conversion in your application program before calling the ESSL subroutine.