dlatzm (l) - Linux Manuals

dlatzm: routine i deprecated and has been replaced by routine DORMRZ

NAME

DLATZM - routine i deprecated and has been replaced by routine DORMRZ

SYNOPSIS

SUBROUTINE DLATZM(
SIDE, M, N, V, INCV, TAU, C1, C2, LDC, WORK )

    
CHARACTER SIDE

    
INTEGER INCV, LDC, M, N

    
DOUBLE PRECISION TAU

    
DOUBLE PRECISION C1( LDC, * ), C2( LDC, * ), V( * ), WORK( * )

PURPOSE

This routine is deprecated and has been replaced by routine DORMRZ. DLATZM applies a Householder matrix generated by DTZRQF to a matrix. Let P = I - tau*u*uaq, u = ( 1 ),

                      ( v )
where v is an (m-1) vector if SIDE = aqLaq, or a (n-1) vector if SIDE = aqRaq.
If SIDE equals aqLaq, let

 C = [ C1 ] 1

     [ C2 ] m-1

       n
Then C is overwritten by P*C.
If SIDE equals aqRaq, let

 C = [ C1, C2 ] m

        1  n-1
Then C is overwritten by C*P.

ARGUMENTS

SIDE (input) CHARACTER*1
= aqLaq: form P * C
= aqRaq: form C * P
M (input) INTEGER
The number of rows of the matrix C.
N (input) INTEGER
The number of columns of the matrix C.
V (input) DOUBLE PRECISION array, dimension
(1 + (M-1)*abs(INCV)) if SIDE = aqLaq (1 + (N-1)*abs(INCV)) if SIDE = aqRaq The vector v in the representation of P. V is not used if TAU = 0.
INCV (input) INTEGER
The increment between elements of v. INCV <> 0
TAU (input) DOUBLE PRECISION
The value tau in the representation of P.
C1 (input/output) DOUBLE PRECISION array, dimension
(LDC,N) if SIDE = aqLaq (M,1) if SIDE = aqRaq On entry, the n-vector C1 if SIDE = aqLaq, or the m-vector C1 if SIDE = aqRaq. On exit, the first row of P*C if SIDE = aqLaq, or the first column of C*P if SIDE = aqRaq.
C2 (input/output) DOUBLE PRECISION array, dimension
(LDC, N) if SIDE = aqLaq (LDC, N-1) if SIDE = aqRaq On entry, the (m - 1) x n matrix C2 if SIDE = aqLaq, or the m x (n - 1) matrix C2 if SIDE = aqRaq. On exit, rows 2:m of P*C if SIDE = aqLaq, or columns 2:m of C*P if SIDE = aqRaq.
LDC (input) INTEGER
The leading dimension of the arrays C1 and C2. LDC >= (1,M).
WORK (workspace) DOUBLE PRECISION array, dimension
(N) if SIDE = aqLaq (M) if SIDE = aqRaq

Pages related to dlatzm

  • dlatzm (3)
  • dlat2s (l) - converts a DOUBLE PRECISION triangular matrix, SA, to a SINGLE PRECISION triangular matrix, A
  • dlatbs (l) - solves one of the triangular systems A *x = s*b or Aaq*x = s*b with scaling to prevent overflow, where A is an upper or lower triangular band matrix
  • dlatdf (l) - uses the LU factorization of the n-by-n matrix Z computed by DGETC2 and computes a contribution to the reciprocal Dif-estimate by solving Z * x = b for x, and choosing the r.h.s
  • dlatps (l) - solves one of the triangular systems A *x = s*b or Aaq*x = s*b with scaling to prevent overflow, where A is an upper or lower triangular matrix stored in packed form
  • dlatrd (l) - reduces NB rows and columns of a real symmetric matrix A to symmetric tridiagonal form by an orthogonal similarity transformation Qaq * A * Q, and returns the matrices V and W which are needed to apply the transformation to the unreduced part of A
  • dlatrs (l) - solves one of the triangular systems A *x = s*b or Aaq*x = s*b with scaling to prevent overflow
  • dlatrz (l) - factors the M-by-(M+L) real upper trapezoidal matrix [ A1 A2 ] = [ A(1:M,1:M) A(1:M,N-L+1:N) ] as ( R 0 ) * Z, by means of orthogonal transformations
  • dla_gbamv (l) - performs one of the matrix-vector operations y := alpha*abs(A)*abs(x) + beta*abs(y),