PSLACP3(l) | LAPACK routine (version 1.5) | PSLACP3(l) |
NAME¶
PSLACP3 - i an auxiliary routine that copies from a global parallel array into a local replicated array or vise versaSYNOPSIS¶
- SUBROUTINE PSLACP3(
- M, I, A, DESCA, B, LDB, II, JJ, REV )
PURPOSE¶
PSLACP3 is an auxiliary routine that copies from a global parallelarray into a local replicated array or vise versa. Notice that
the entire submatrix that is copied gets placed on one node or
more. The receiving node can be specified precisely, or all nodes
can receive, or just one row or column of nodes.
DTYPE_A = 1.
the BLACS process grid A is distribu-
ted over. The context itself is glo-
bal, but the handle (the integer
value) may vary.
array A.
array A.
the rows of the array.
the columns of the array.
row of the array A is distributed. CSRC_A (global) DESCA( CSRC_ ) The process column over which the
first column of the array A is
distributed.
array. LLD_A >= MAX(1,LOCr(M_A)). Let K be the number of rows or columns of a distributed matrix, and assume that its process grid has dimension p x q.
LOCr( M ) = NUMROC( M, MB_A, MYROW, RSRC_A, NPROW ),
LOCc( N ) = NUMROC( N, NB_A, MYCOL, CSRC_A, NPCOL ). An upper bound for these quantities may be computed by:
LOCr( M ) <= ceil( ceil(M/MB_A)/NPROW )*MB_A
LOCc( N ) <= ceil( ceil(N/NB_A)/NPCOL )*NB_A
ARGUMENTS¶
- M (global input) INTEGER
- M is the order of the square submatrix that is copied. M >= 0. Unchanged on exit
- I (global input) INTEGER
- A(I,I) is the global location that the copying starts from. Unchanged on exit.
- A (global input/output) REAL array, dimension
- (DESCA(LLD_),*) On entry, the parallel matrix to be copied into or from. On exit, if REV=1, the copied data. Unchanged on exit if REV=0.
- DESCA (global and local input) INTEGER array of dimension DLEN_.
- The array descriptor for the distributed matrix A.
- B (local input/output) REAL array of size (LDB,M)
- If REV=0, this is the global portion of the array A(I:I+M-1,I:I+M-1). If REV=1, this is the unchanged on exit.
- LDB (local input) INTEGER
- The leading dimension of B.
- II (global input) INTEGER
- By using REV 0 & 1, data can be sent out and returned again. If REV=0, then II is destination row index for the node(s) receiving the replicated B. If II>=0,JJ>=0, then node (II,JJ) receives the data If II=-1,JJ>=0, then all rows in column JJ receive the data If II>=0,JJ=-1, then all cols in row II receive the data If II=-1,JJ=-1, then all nodes receive the data If REV<>0, then II is the source row index for the node(s) sending the replicated B.
- JJ (global input) INTEGER
- Similar description as II above
- REV (global input) INTEGER
- Use REV = 0 to send global A into locally replicated B (on node (II,JJ)). Use REV <> 0 to send locally replicated B from node (II,JJ) to its owner (which changes depending on its location in A) into the global A. Implemented by: G. Henry, May 1, 1997
12 May 1997 | LAPACK version 1.5 |