NAME

       PCLAEVSWP  - move the eigenvectors (potentially unsorted) from where they are computed, to
       a ScaLAPACK standard block cyclic array, sorted so that the corresponding eigenvalues  are
       sorted

SYNOPSIS

       SUBROUTINE PCLAEVSWP( N, ZIN, LDZI, Z, IZ, JZ, DESCZ, NVS, KEY, RWORK, LRWORK )

           INTEGER           IZ, JZ, LDZI, LRWORK, N

           INTEGER           DESCZ( * ), KEY( * ), NVS( * )

           REAL              RWORK( * ), ZIN( LDZI, * )

           COMPLEX           Z( * )

PURPOSE

       PCLAEVSWP moves the eigenvectors (potentially unsorted) from where they are computed, to a
       ScaLAPACK standard block cyclic array, sorted so that the  corresponding  eigenvalues  are
       sorted.

       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 = the number of rows local to a given process.  NQ = the number of columns local  to  a
       given process.

       N       (global input) INTEGER
               The order of the matrix A.  N >= 0.

       ZIN     (local input) REAL array,
               dimension  ( LDZI, NVS(iam) ) The eigenvectors on input.  Each eigenvector resides
               entirely in one  process.   Each  process  holds  a  contiguous  set  of  NVS(iam)
               eigenvectors.   The  first  eigenvector  which  the  process  holds  is:   sum for
               i=[0,iam-1) of NVS(i)

       LDZI    (locl input) INTEGER
               leading dimension of the ZIN array

       Z       (local output) COMPLEX array
               global dimension (N, N), local dimension (DESCZ(DLEN_), NQ)  The  eigenvectors  on
               output.   The  eigenvectors  are  distributed  in  a  block  cyclic manner in both
               dimensions, with a block size of NB.

       IZ      (global input) INTEGER
               Z's global row index, which points to the beginning of the submatrix which  is  to
               be operated on.

       JZ      (global input) INTEGER
               Z's  global  column index, which points to the beginning of the submatrix which is
               to be operated on.

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

       NVS     (global input) INTEGER array, dimension( nprocs+1 )
               nvs(i) = number of processes number of  eigenvectors  held  by  processes  [0,i-1)
               nvs(1)  =  number  of eigen vectors held by [0,1-1) == 0 nvs(nprocs+1) = number of
               eigen vectors held by [0,nprocs) == total number of eigenvectors

       KEY     (global input) INTEGER array, dimension( N )
               Indicates the actual index (after sorting) for each of the eigenvectors.

       RWORK    (local workspace) REAL array, dimension (LRWORK)

       LRWORK   (local input) INTEGER dimension of RWORK