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Initialize the Process Grid

 

A call to the ScaLAPACK TOOLS routine SL_INIT initializes the process grid. This routine initializes a tex2html_wrap_inline12182 (denoted tex2html_wrap_inline12614 in the source code) process grid by using a row-major ordering of the processes, and obtains a default system context . For more information on contexts, refer to section 4.1.2 or [54].

The user can then query the process grid to identify each process's coordinates (MYROW,MYCOL)  )   via a call to BLACS_GRIDINFO .

A typical code fragment (as obtained from the example program in section 2.3) to accomplish this task would be the following:

      CALL SL_INIT( ICTXT, NPROW, NPCOL )
      CALL BLACS_GRIDINFO( ICTXT, NPROW, NPCOL, MYROW, MYCOL )

where details of the calling sequence for SL_INIT are provided below. Detailed descriptions of calling sequences for each BLACS routine can be found in [54] and Appendix D.3. Note that underlined arguments in the calling sequence denote output arguments.

For a description of these variables names, please refer to the example program notation in section 2.3 and [54].



Susan Blackford
Tue May 13 09:21:01 EDT 1997