Parallel Engineering and Scientific Subroutine Library for AIX Version 2 Release 3: Guide and Reference

PGEALL--Allocates Space for a Dense Vector

This sparse utility subroutine allocates space for a dense vector.

Syntax

On Entry

x

See On Return.

desc_a

is the array descriptor that is produced on a preceding call to PADALL.

Type: required

Specified as: the derived data type DESC_TYPE.

On Return

x

is a pointer to the local space of the dense vector.

Scope: local

Type: required

Returned as: a pointer to an assumed-shape array with shape (:), containing long-precision real numbers.

Notes and Coding Rules

1. Before you call this subroutine, you must have called PADALL.
2. You do not need a separate array descriptor for a dense vector because it must conform to the size of matrix A. For details about some of the elements stored in DESC_A%MATRIX_DATA, see Derived Data Type DESC_TYPE.
3. This subroutine must be called for:
   • Vector b containing the right-hand side.
   • Vector x containing the initial guess to the solution.
4. PGEALL allocates the dense vector as necessary. Prior to further calls to PGEALL with the same dense vector, you must call PGEFREE; otherwise, there will be a memory leak.

Error Conditions

Computational Errors

None

Resource Errors

1. Unable to allocate the dense vector.

Input-Argument and Miscellaneous Errors

Stage 1:  

1. desc_a has not been initialized.

Stage 2:  

1. The BLACS context is invalid.

Stage 3:  

1. This subroutine was called from outside the process grid.

Stage 4:  

1. The process grid is not np × 1.
2. desc_a component(s) are not valid.