..
     .. Array Arguments ..
     ..
  Purpose:
  ========
  PCLASWP performs a series of row or column interchanges on
  the distributed matrix sub( A ) = A(IA:IA+M-1,JA:JA+N-1).  One
  interchange is initiated for each of rows or columns K1 trough K2 of
  sub( A ). This routine assumes that the pivoting information has
  already been broadcast along the process row or column.
  Also note that this routine will only work for K1-K2 being in the
  same MB (or NB) block.  If you want to pivot a full matrix, use
  PCLAPIV.
  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
  =========
  DIREC   (global input) CHARACTER
          Specifies in which order the permutation is applied:
          = 'F' (Forward)
          = 'B' (Backward)
  ROWCOL  (global input) CHARACTER
          Specifies if the rows or columns are permuted:
          = 'R' (Rows)
          = 'C' (Columns)
  N       (global input) INTEGER
          If ROWCOL = 'R', the length of the rows of the distributed
          matrix A(*,JA:JA+N-1) to be permuted;
          If ROWCOL = 'C', the length of the columns of the distributed
          matrix A(IA:IA+N-1,*) to be permuted.
  A       (local input/local output) COMPLEX pointer into the
          local memory to an array of dimension (LLD_A, * ).
          On entry, this array contains the local pieces of the distri-
          buted matrix to which the row/columns interchanges will be
          applied. On exit the permuted distributed matrix.
  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.
  K1      (global input) INTEGER
          The first element of IPIV for which a row or column inter-
          change will be done.
  K2      (global input) INTEGER
          The last element of IPIV for which a row or column inter-
          change will be done.
  IPIV    (local input) INTEGER array, dimension LOCr(M_A)+MB_A for
          row pivoting and LOCc(N_A)+NB_A for column pivoting.  This
          array is tied to the matrix A, IPIV(K) = L implies rows
          (or columns) K and L are to be interchanged.
  =====================================================================
     .. Parameters ..