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



NAME
       BDLAAPP - computes B = Q**T * A       or       B = A * Q, where A is an
       M-by-N matrix and Q is an orthogonal matrix represented by the  parame-
       ters in the arrays ITRAF and DTRAF as described in BDTREXC

SYNOPSIS
       SUBROUTINE BDLAAPP( ISIDE, M, N, NB, A, LDA, NITRAF, ITRAF, DTRAF, WORK
                           )

           INTEGER         ISIDE, LDA, M, N, NB, NITRAF

           INTEGER         ITRAF( * )

           DOUBLE          PRECISION A( LDA, * ), DTRAF( * ), WORK( * )

PURPOSE
       BDLAAPP computes

               B = Q**T * A       or       B = A * Q,

       where A is an M-by-N matrix and Q is an orthogonal  matrix  represented
       by  the  parameters  in  the  arrays  ITRAF  and  DTRAF as described in
       BDTREXC.

       This is an auxiliary routine called by BDTRSEN.


ARGUMENTS
       ISIDE   (input) INTEGER
               Specifies whether Q multiplies A from the left or right as fol-
               lows:
               = 0: compute B = Q**T * A;
               = 1: compute B = A * Q.

       M       (input) INTEGER
               The number of rows of A.

       N       (input) INTEGER
               The number of columns of A.

       NB      (input) INTEGER
               If ISIDE = 0, the Q is applied block column-wise to the rows of
               A and NB specifies the maximal width of the block columns.
               If ISIDE = 1, this variable is not referenced.

       A       (input/output) DOUBLE PRECISION array, dimension (LDA,N)
               On entry, the matrix A.
               On exit, A is overwritten by B.

       LDA     (input) INTEGER
               The leading dimension of the array A. LDA >= max(1,N).

       NITRAF  (input) INTEGER
               Length of the array ITRAF. NITRAF >= 0.

       ITRAF   (input) INTEGER array, length NITRAF
               List of parameters for representing the  transformation  matrix
               Q, see BDTREXC.

       DTRAF   (output) DOUBLE PRECISION array, length k, where
               List  of  parameters for representing the transformation matrix
               Q, see BDTREXC.

       WORK    (workspace) DOUBLE PRECISION array, dimension (N)



ScaLAPACK routine               31 October 2017                     BDLAAPP(3)