BLACS -- Advanced Topics
CALL BLACS_GRIDINFO( ICTXT, NPROW, NPCOL, MYROW, MYCOL )
IF( MYROW.EQ.0 .AND. MYCOL.EQ.0 ) THEN
CALL DGESD2D( ICTXT, 5, 1, X, 5, 1, 0 )
CALL DGERV2D( ICTXT, 5, 1, X, 5, 1, 0 )
ELSE IF( MYROW.EQ.1 .AND. MYCOL.EQ.0 ) THEN
CALL DGESD2D( ICTXT, 5, 1, X, 5, 0, 0 )
CALL DGERV2D( ICTXT, 5, 1, X, 5, 0, 0 )