Description

S3L_declare_sparse creates an internal S3L array handle that describes a sparse matrix. The sparse matrix may be represented in either the Coordinate format or the Compressed Sparse Row (CSR) format. Upon successful completion, S3L_declare_sparse returns an S3L array handle in A that describes the distributed sparse matrix.

The Coordinate format consists of three arrays: a, r, and c. Array a stores the nonzero elements of the sparse matrix in any order. r and c are integer arrays that hold the corresponding row and column indices of the sparse matrix, respectively.

The contents of r, c, and a are supplied by the arguments row, col, and val, respectively. row, col, and val are all rank 1 parallel arrays.

The CSR format stores the sparse matrix in arrays ia, ja, and a. As with the Coordinate format, array a stores the nonzero elements of the matrix. ja, an integer array, contains the column indices of the nonzeros as stored in the array a. ia, also an integer array, contains pointers to the beginning of each row in arrays a and ja.

The ia, ja, and a arrays take their contents from the row, col, and val arguments, respectively. As with the Coordinate format, row, col, and val are all rank 1 parallel arrays.

Because row, col, and val are copied to working arrays, they can be deallocated immediately following the S3L_declare_sparse call.

S3L_declare_sparse assumes that the row and column indices of the sparse matrix are stored using zero-based indexing when called by C or C++ applications and one-based indexing when called by F77 or F90 applications. See "S3L_read_sparse " for a discussion of S3L_read_sparse.