NAME

       PDLARED2D  -  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 PDLARED2D( N, IA, JA, DESC, BYROW, BYALL, WORK, LWORK )

           INTEGER           IA, JA, LWORK, N

           INTEGER           DESC( * )

           DOUBLE            PRECISION BYALL( * ), BYROW( * ), WORK( LWORK )

PURPOSE

       PDLARED2D 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 DOUBLE PRECISION 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) DOUBLE PRECISION 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) DOUBLE PRECISION 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)