psb_info -- Return information about PSBLAS parallel environment

call psb_info(icontxt, iam, np)

This subroutine returns information about the PSBLAS parallel environment, defining a virtual parallel machine.

Type:

Asynchronous.

On Entry

icontxt

the communication context identifying the virtual parallel machine.
Scope: global.
Type: required.
Intent: in.
Specified as: an integer variable.

On Return

iam

Identifier of current process in the PSBLAS virtual parallel machine.
Scope: local.
Type: required.
Intent: out.
Specified as: an integer value. $-1 \le iam \le np-1$

np

Number of processes in the PSBLAS virtual parallel machine.
Scope: global.
Type: required.
Intent: out.
Specified as: an integer variable.

Notes

1. For processes in the virtual parallel machine the identifier will satisfy $0 \le iam \le np-1$;
2. If the user has requested on psb_init a number of processes less than the total available in the parallel execution environment, the remaining processes will have on return $iam=-1$; the only call involving icontxt that any such process may execute is to psb_exit.