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 BYROW

SYNOPSIS

       SUBROUTINE PSLARED2D( N, IA, JA, DESC, BYROW, BYALL, WORK, LWORK )

           INTEGER           IA, JA, LWORK, N

           INTEGER           DESC( * )

           REAL              BYALL( * ), BYROW( * ), WORK( LWORK )

PURPOSE

       PSLARED2D redistributes a 1D array and will contain the entire array.

       Notes
       =====

       Each global data object is described by an associated  description  vector.   This  vector
       stores the information required to establish the mapping 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 column.
       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

       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)