PSLARED2D(l) | LAPACK routine (version 1.5) | PSLARED2D(l) |
NAME¶
PSLARED2D - redistribute a 1D array It assumes that the input array, BYROW, is distributed across columns and that all process rows contain the same copy of BYROWSYNOPSIS¶
- SUBROUTINE PSLARED2D(
- N, IA, JA, DESC, BYROW, BYALL, WORK, LWORK )
PURPOSE¶
PSLARED2D redistributes a 1D array and will contain the entire array.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¶
NP = Number of local rows in BYROW()- N (global input) INTEGER
- The number of elements to be redistributed. N >= 0.
- IA (global input) INTEGER
- IA must be equal to 1
- JA (global input) INTEGER
- JA must be equal to 1
- DESC (global/local input) INTEGER Array of dimension DLEN_
- A 2D array descriptor, which describes BYROW
- BYROW (local input) distributed block cyclic REAL array
- global dimension (N), local dimension NP BYCOL is distributed across the process columns All process rows are assumed to contain the same value
- BYALL (global output) REAL global dimension( N )
- local dimension (N) BYALL is exactly duplicated on all processes It contains the same values as BYCOL, but it is replicated across all processes rather than being distributed BYALL(i) = BYCOL( NUMROC(i,NB,MYROW,0,NPROW ) on the procs whose MYROW == mod((i-1)/NB,NPROW)
- WORK (local workspace) REAL dimension (LWORK)
- Used to hold the buffers sent from one process to another
- LWORK (local input) INTEGER size of WORK array LWORK >=
- LWORK >= NUMROC(N, DESC( NB_ ), 0, 0, NPCOL)
12 May 1997 | LAPACK version 1.5 |