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psb_init -- Initializes PSBLAS parallel environment

call psb_init(icontxt, np)

This subroutine initializes the PSBLAS parallel environment, defining a virtual parallel machine.

Type:
Synchronous.
On Entry
np
Number of processes in the PSBLAS virtual parallel machine.
Scope: global.
Type: optional.
Intent: in.
Specified as: an integer value. Default: use all available processes provided by the underlying parallel environment.

On Return
icontxt
the communication context identifying the virtual parallel machine.
Scope: global.
Type: required.
Intent: out.
Specified as: an integer variable.

Notes

  1. A call to this routine must precede any other PSBLAS call.
  2. It is an error to specify a value for $np$ greater than the number of processes available in the underlying parallel execution environment.