• NAME
• SYNOPSIS
• F95 INTERFACE
• C INTERFACE
• PURPOSE
• ARGUMENTS

NAME

zunmhr - overwrite the general complex M-by-N matrix C with SIDE = 'L' SIDE = 'R' TRANS = 'N'

SYNOPSIS

  SUBROUTINE ZUNMHR( SIDE, TRANS, M, N, ILO, IHI, A, LDA, TAU, C, LDC, 
 *      WORK, LWORK, INFO)
  CHARACTER * 1 SIDE, TRANS
  DOUBLE COMPLEX A(LDA,*), TAU(*), C(LDC,*), WORK(*)
  INTEGER M, N, ILO, IHI, LDA, LDC, LWORK, INFO

  SUBROUTINE ZUNMHR_64( SIDE, TRANS, M, N, ILO, IHI, A, LDA, TAU, C, 
 *      LDC, WORK, LWORK, INFO)
  CHARACTER * 1 SIDE, TRANS
  DOUBLE COMPLEX A(LDA,*), TAU(*), C(LDC,*), WORK(*)
  INTEGER*8 M, N, ILO, IHI, LDA, LDC, LWORK, INFO

F95 INTERFACE

  SUBROUTINE UNMHR( SIDE, [TRANS], [M], [N], ILO, IHI, A, [LDA], TAU, 
 *       C, [LDC], [WORK], [LWORK], [INFO])
  CHARACTER(LEN=1) :: SIDE, TRANS
  COMPLEX(8), DIMENSION(:) :: TAU, WORK
  COMPLEX(8), DIMENSION(:,:) :: A, C
  INTEGER :: M, N, ILO, IHI, LDA, LDC, LWORK, INFO

  SUBROUTINE UNMHR_64( SIDE, [TRANS], [M], [N], ILO, IHI, A, [LDA], 
 *       TAU, C, [LDC], [WORK], [LWORK], [INFO])
  CHARACTER(LEN=1) :: SIDE, TRANS
  COMPLEX(8), DIMENSION(:) :: TAU, WORK
  COMPLEX(8), DIMENSION(:,:) :: A, C
  INTEGER(8) :: M, N, ILO, IHI, LDA, LDC, LWORK, INFO

C INTERFACE

#include <sunperf.h>

void zunmhr(char side, char trans, int m, int n, int ilo, int ihi, doublecomplex *a, int lda, doublecomplex *tau, doublecomplex *c, int ldc, int *info);

void zunmhr_64(char side, char trans, long m, long n, long ilo, long ihi, doublecomplex *a, long lda, doublecomplex *tau, doublecomplex *c, long ldc, long *info);

PURPOSE

zunmhr overwrites the general complex M-by-N matrix C with 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 IHI-ILO elementary reflectors, as returned by CGEHRD:

Q = H(ilo) H(ilo+1) . . . H(ihi-1).

ARGUMENTS

• SIDE (input)
  

   = 'L': apply Q or Q**H from the Left;

   = 'R': apply Q or Q**H from the Right.

• TRANS (input)
  

   = 'N': apply Q  (No transpose)

   = 'C': apply Q**H (Conjugate transpose)

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

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

• ILO (input)
  ILO and IHI must have the same values as in the previous call of CGEHRD. Q is equal to the unit matrix except in the submatrix Q(ilo+1:ihi,ilo+1:ihi). If SIDE = 'L', then 1 < = ILO < = IHI < = M, if M > 0, and ILO = 1 and IHI = 0, if M = 0; if SIDE = 'R', then 1 < = ILO < = IHI < = N, if N > 0, and ILO = 1 and IHI = 0, if N = 0.

• IHI (input)
  See the description of ILO.

• A (input)
  (LDA,M) if SIDE = 'L' (LDA,N) if SIDE = 'R' The vectors which define the elementary reflectors, as returned by CGEHRD.

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

• TAU (input)
  (M-1) if SIDE = 'L' (N-1) if SIDE = 'R' TAU(i) must contain the scalar factor of the elementary reflector H(i), as returned by CGEHRD.

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

• WORK (workspace)
  On exit, if INFO = 0, WORK(1) returns the optimal LWORK.

• LWORK (input)
  The dimension of the array WORK. If SIDE = 'L', LWORK > = max(1,N); if SIDE = 'R', LWORK > = max(1,M). For optimum performance LWORK > = N*NB if SIDE = 'L', and LWORK > = M*NB if SIDE = 'R', where NB is the optimal blocksize.

  If LWORK = -1, then a workspace query is assumed; the routine only calculates the optimal size of the WORK array, returns this value as the first entry of the WORK array, and no error message related to LWORK is issued by XERBLA.

• INFO (output)
  

   = 0:  successful exit

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