SCALAPACK 2.2.2
LAPACK: Linear Algebra PACKage
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◆ PB_Cindxg2p()

Int PB_Cindxg2p ( Int  IG,
Int  INB,
Int  NB,
Int  PROC,
Int  SRCPROC,
Int  NPROCS 
)

Definition at line 22 of file PB_Cindxg2p.c.

28{
29/*
30* Purpose
31* =======
32*
33* PB_Cindxg2p computes the process coordinate which posseses the entry
34* of a matrix specified by a global index IG.
35*
36* Arguments
37* =========
38*
39* IG (global input) INTEGER
40* On entry, IG specifies the global index of the matrix entry.
41* IG must be at least zero.
42*
43* INB (global input) INTEGER
44* On entry, INB specifies the size of the first block of the
45* global matrix. INB must be at least one.
46*
47* NB (global input) INTEGER
48* On entry, NB specifies the size of the blocks used to parti-
49* tion the matrix. NB must be at least one.
50*
51* PROC (local dummy) INTEGER
52* On entry, PROC is a dummy argument in this case in order to
53* unify the calling sequence of the tool-routines.
54*
55* SRCPROC (global input) INTEGER
56* On entry, SRCPROC specifies the coordinate of the process
57* that possesses the first row or column of the matrix. When
58* SRCPROC = -1, the data is not distributed but replicated,
59* otherwise SRCPROC must be at least zero and strictly less
60* than NPROCS.
61*
62* NPROCS (global input) INTEGER
63* On entry, NPROCS specifies the total number of process rows
64* or columns over which the matrix is distributed. NPROCS must
65* be at least one.
66*
67* -- Written on April 1, 1998 by
68* Antoine Petitet, University of Tennessee, Knoxville 37996, USA.
69*
70* ---------------------------------------------------------------------
71*/
72/* ..
73* .. Executable Statements ..
74*
75*/
76 if( ( IG < INB ) || ( SRCPROC == -1 ) || ( NPROCS == 1 ) )
77/*
78* IG belongs to the first block, or the data is not distributed, or there is
79* just one process in this dimension of the grid.
80*/
81 return( SRCPROC );
82/*
83* Otherwise, IG is in block 1 + ( IG - INB ) / NB. Add this to SRCPROC and
84* take the NPROCS modulo (definition of the block-cyclic data distribution).
85*/
86 PROC = SRCPROC + 1 + ( IG - INB ) / NB;
87 return( MPosMod( PROC, NPROCS ) );
88/*
89* End of PB_Cindxg2p
90*/
91}
MPosMod
#define MPosMod(I, d)
Definition PBtools.h:95