cunm2l(3)

NAME

cunm2l.f –

SYNOPSIS

Functions/Subroutines

subroutine cunm2l (SIDE, TRANS, M, N, K, A, LDA, TAU, C, LDC, WORK, INFO)
CUNM2L multiplies a general matrix by the unitary matrix from a QL factorization determined by cgeqlf (unblocked algorithm).

Function/Subroutine Documentation

subroutine cunm2l (characterSIDE, characterTRANS, integerM, integerN, integerK, complex, dimension( lda, * )A, integerLDA, complex, dimension( * )TAU, complex, dimension( ldc, * )C, integerLDC, complex, dimension( * )WORK, integerINFO)

CUNM2L multiplies a general matrix by the unitary matrix from a QL factorization determined by cgeqlf (unblocked algorithm).

Purpose:

CUNM2L overwrites the general complex m - by - n matrix C with Q *C if SIDE = 'L' and TRANS = 'N', or
                                                                                                       Q **H *C if SIDE = 'L' and TRANS = 'C',
                                                                       or
                                                                           C *Q if SIDE = 'R' and TRANS = 'N',
                                                                       or
                                                                           C *Q **H if SIDE = 'R' and TRANS = 'C',
                                                                       where Q is a complex unitary matrix defined as the product of k
                                                                           elementary reflectors
                                                                               Q = H(k)...H(2) H(1)
                                                                                       as returned by CGEQLF.Q is of order m if SIDE = 'L' and of order n if SIDE = 'R'.

 

Parameters:

SIDE

          SIDE is CHARACTER*1
          = 'L': apply Q or Q**H from the Left
          = 'R': apply Q or Q**H from the Right

TRANS

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

M

          M is INTEGER
          The number of rows of the matrix C. M >= 0.

N

          N is INTEGER
          The number of columns of the matrix C. N >= 0.

K

K is 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

          A is COMPLEX array, dimension (LDA,K)
          The i-th column must contain the vector which defines the
          elementary reflector H(i), for i = 1,2,...,k, as returned by
          CGEQLF in the last k columns of its array argument A.
          A is modified by the routine but restored on exit.

LDA

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

TAU

          TAU is COMPLEX array, dimension (K)
          TAU(i) must contain the scalar factor of the elementary
          reflector H(i), as returned by CGEQLF.

C

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

LDC

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

WORK

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

INFO

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

 

Author:

Univ. of Tennessee

Univ. of California Berkeley

Univ. of Colorado Denver

NAG Ltd.

Date:

September 2012

Definition at line 159 of file cunm2l.f.

Author

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