cupmtr(3)

NAME

cupmtr.f –

SYNOPSIS

Functions/Subroutines

subroutine cupmtr (SIDE, UPLO, TRANS, M, N, AP, TAU, C, LDC, WORK, INFO)
CUPMTR

Function/Subroutine Documentation

subroutine cupmtr (characterSIDE, characterUPLO, characterTRANS, integerM, integerN, complex, dimension( * )AP, complex, dimension( * )TAU, complex, dimension( ldc, * )C, integerLDC, complex, dimension( * )WORK, integerINFO)

CUPMTR

Purpose:

CUPMTR overwrites the general complex M - by - N matrix C with SIDE = 'L' SIDE = 'R' TRANS = 'N' : Q *C C *Q
                                                                                                       TRANS = 'C' : Q * *H * C C * Q * *H where Q is a complex unitary matrix of order nq,
                                                               with nq = m if SIDE = 'L' and nq = n if SIDE = 'R'.Q is defined as the product of
                                                                                                                  nq -
                                                                                                              1 elementary reflectors,
                                                               as returned by CHPTRD using packed
                                                                   storage : if UPLO = 'U',
                                                               Q = H(nq - 1)...H(2) H(1);
if UPLO
= 'L', Q = H(1) H(2)...H(nq - 1).

 

Parameters:

SIDE

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

UPLO

          UPLO is CHARACTER*1
          = 'U': Upper triangular packed storage used in previous
                 call to CHPTRD;
          = 'L': Lower triangular packed storage used in previous
                 call to CHPTRD.

TRANS

          TRANS is CHARACTER*1
          = 'N':  No transpose, apply Q;
          = 'C':  Conjugate transpose, apply Q**H.

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.

AP

          AP is COMPLEX array, dimension
                               (M*(M+1)/2) if SIDE = 'L'
                               (N*(N+1)/2) if SIDE = 'R'
          The vectors which define the elementary reflectors, as
          returned by CHPTRD.  AP is modified by the routine but
          restored on exit.

TAU

          TAU is COMPLEX array, dimension (M-1) if SIDE = 'L'
                                     or (N-1) if SIDE = 'R'
          TAU(i) must contain the scalar factor of the elementary
          reflector H(i), as returned by CHPTRD.

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:

November 2011

Definition at line 150 of file cupmtr.f.

Author

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