


CUNM2R(3f)         LAPACK routine (version 3.1)        CUNM2R(3f)


NAME
       CUNM2R - the general complex m-by-n matrix C with   Q * C if SIDE = 'L'
       and TRANS = 'N', or   Q'* C if SIDE = 'L' and TRANS = 'C', or   C  *  Q
       if  SIDE  =  'R' and TRANS = 'N', or   C * Q' if SIDE = 'R' and TRANS =
       'C',

SYNOPSIS
       SUBROUTINE CUNM2R( SIDE, TRANS, M, N, K, A, LDA,  TAU,  C,  LDC,  WORK,
                          INFO )

           CHARACTER      SIDE, TRANS

           INTEGER        INFO, K, LDA, LDC, M, N

           COMPLEX        A( LDA, * ), C( LDC, * ), TAU( * ), WORK( * )

PURPOSE
       CUNM2R overwrites the general complex m-by-n matrix C with

       where Q is a complex unitary matrix defined as the product of k elemen-
       tary reflectors

             Q = H(1) H(2) . . . H(k)

       as returned by CGEQRF. Q is of order m if SIDE = 'L' and of order n  if
       SIDE = 'R'.


ARGUMENTS
       SIDE    (input) CHARACTER*1
               = 'L': apply Q or Q' from the Left
               = 'R': apply Q or Q' from the Right

       TRANS   (input) CHARACTER*1
               = 'N': apply Q  (No transpose)
               = 'C': apply Q' (Conjugate transpose)

       M       (input) INTEGER
               The number of rows of the matrix C. M >= 0.

       N       (input) INTEGER
               The number of columns of the matrix C. N >= 0.

       K       (input) INTEGER
               The  number  of elementary reflectors whose product defines the
               matrix Q.  If SIDE = 'L', M >= K >= 0; if SIDE = 'R', N >= K >=
               0.

       A       (input) COMPLEX array, dimension (LDA,K)
               The  i-th column must contain the vector which defines the ele-
               mentary reflector H(i), for i = 1,2,...,k, as returned by  CGE-
               QRF in the first k columns of its array argument A.  A is modi-
               fied by the routine but restored on exit.




 LAPACK routine (version 3November 2006                         1





CUNM2R(3f)         LAPACK routine (version 3.1)        CUNM2R(3f)


       LDA     (input) INTEGER
               The leading dimension of the array A.  If SIDE =  'L',  LDA  >=
               max(1,M); if SIDE = 'R', LDA >= max(1,N).

       TAU     (input) COMPLEX array, dimension (K)
               TAU(i) must contain the scalar factor of the elementary reflec-
               tor H(i), as returned by CGEQRF.

       C       (input/output) COMPLEX array, dimension (LDC,N)
               On entry, the m-by-n matrix C.  On exit, C  is  overwritten  by
               Q*C or Q'*C or C*Q' or C*Q.

       LDC     (input) INTEGER
               The leading dimension of the array C. LDC >= max(1,M).

       WORK    (workspace) COMPLEX array, dimension
               (N) if SIDE = 'L', (M) if SIDE = 'R'

       INFO    (output) INTEGER
               = 0: successful exit
               < 0: if INFO = -i, the i-th argument had an illegal value




































 LAPACK routine (version 3November 2006                         2


