psb_spall -- Allocates a sparse matrix

call psb_spall(a, desc_a, info, nnz)

Type:

Synchronous.

On Entry

desc_a

the communication descriptor.
Scope:local.
Type:required.
Intent: in.
Specified as: a structured data of type descdatapsb_desc_type.

nnz

An estimate of the number of nonzeroes in the local part of the assembled matrix.
Scope: global.
Type: optional.
Intent: in.
Specified as: an integer value.

On Return

a

the matrix to be allocated.
Scope:local
Type:required
Intent: out.
Specified as: a structured data of type spdatapsb_spmat_type.

info

Error code.
Scope: local
Type: required
Intent: out.
An integer value; 0 means no error has been detected.

Notes

1. On exit from this routine the sparse matrix is in the build state.
2. The descriptor may be in either the build or assembled state.
3. Providing a good estimate for the number of nonzeroes $nnz$ in the assembled matrix may substantially improve performance in the matrix build phase, as it will reduce or eliminate the need for (potentially multiple) data reallocations.