PSLAMVE(3)    ScaLAPACK routine of NEC Numeric Library Collection   PSLAMVE(3)



NAME
       PSLAMVE  - copies all or part of a distributed matrix A to another dis-
       tributed matrix B

SYNOPSIS
       SUBROUTINE PSLAMVE( UPLO, M, N, A, IA, JA, DESCA,  B,  IB,  JB,  DESCB,
                           DWORK )

           CHARACTER       UPLO

           INTEGER         IA, IB, JA, JB, M, N

           INTEGER         DESCA( * ), DESCB( * )

           REAL            A( * ), B( * ), DWORK( * )

PURPOSE
       PSLAMVE  copies  all  or part of a distributed matrix A to another dis-
       tributed matrix B. There is no alignment assumptions at all except that
       A and B are of the same size.


       Notes
       =====

       Each  global data object is described by an associated description vec-
       tor.  This vector stores the information required to establish the map-
       ping between an object element and its corresponding process and memory
       location.

       Let A be a generic term for any 2D block cyclicly distributed array.
       Such a global array has an associated description vector DESCA.
       In the following comments, the character _ should be read  as  "of  the
       global array".

       NOTATION        STORED IN      EXPLANATION
       --------------- -------------- --------------------------------------
       DTYPE_A(global) DESCA( DTYPE_ )The descriptor type.  In this case,
                                      DTYPE_A = 1.
       CTXT_A (global) DESCA( CTXT_ ) The BLACS context handle, indicating
                                      the BLACS process grid A is distribu-
                                      ted over. The context itself is glo-
                                      bal, but the handle (the integer
                                      value) may vary.
       M_A    (global) DESCA( M_ )    The number of rows in the global
                                      array A.
       N_A    (global) DESCA( N_ )    The number of columns in the global
                                      array A.
       MB_A   (global) DESCA( MB_ )   The blocking factor used to distribute
                                      the rows of the array.
       NB_A   (global) DESCA( NB_ )   The blocking factor used to distribute
                                      the columns of the array.
       RSRC_A (global) DESCA( RSRC_ ) The process row over which the first
                                      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.
       LLD_A  (local)  DESCA( LLD_ )  The leading dimension of the local
                                      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( K ) denotes the number of elements of  K  that  a  process  would
       receive  if K were distributed over the p processes of its process col-
       umn.
       Similarly, LOCc( K ) denotes the number of elements of K that a process
       would receive if K were distributed over the q processes of its process
       row.
       The values of LOCr() and LOCc() may be determined via  a  call  to  the
       ScaLAPACK tool function, NUMROC:
              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
       UPLO    (global input) CHARACTER
               Specifies the part of the distributed matrix sub(  A  )  to  be
               copied:
               = 'U':   Upper triangular part is copied; the strictly
                          lower triangular part of sub( A ) is not referenced;
               = 'L':   Lower triangular part is copied; the strictly
                          upper triangular part of sub( A ) is not referenced;
               Otherwise:  All of the matrix sub( A ) is copied.

       M       (global input) INTEGER
               The  number of rows to be operated on i.e the number of rows of
               the distributed submatrix sub( A ). M >= 0.

       N       (global input) INTEGER
               The number of columns to be  operated  on  i.e  the  number  of
               columns of the distributed submatrix sub( A ). N >= 0.

       A       (local input) REAL pointer into the local memory
               to  an  array  of  dimension (LLD_A, LOCc(JA+N-1) ). This array
               contains the local pieces of the distributed matrix sub( A ) to
               be copied from.

       IA      (global input) INTEGER
               The row index in the global array A indicating the first row of
               sub( A ).

       JA      (global input) INTEGER
               The column index in the global array  A  indicating  the  first
               column of sub( A ).

       DESCA   (global and local input) INTEGER array of dimension DLEN_.
               The array descriptor for the distributed matrix A.

       B       (local output) REAL pointer into the local memory
               to  an  array  of  dimension (LLD_B, LOCc(JB+N-1) ). This array
               contains on exit the local pieces  of  the  distributed  matrix
               sub( B ).

       IB      (global input) INTEGER
               The row index in the global array B indicating the first row of
               sub( B ).

       JB      (global input) INTEGER
               The column index in the global array  B  indicating  the  first
               column of sub( B ).

       DESCB   (global and local input) INTEGER array of dimension DLEN_.
               The array descriptor for the distributed matrix B.

       DWORK   (local workspace) REAL array
               If UPLO = 'U' or UPLO = 'L' and number of processors > 1,
               the length of DWORK is at least as large as the length of B.
               Otherwise, DWORK is not referenced.



ScaLAPACK routine               31 October 2017                     PSLAMVE(3)