Provided by: liblapack-doc_3.3.1-1_all

**NAME**

LAPACK-3 - routine i deprecated and has been replaced by routine DORMRZ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This routine is deprecated and has been replaced by routine DORMRZ.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*u**T, u = ( 1 ), ( v ) where v is an (m-1) vector if SIDE = 'L', or a (n-1) vector if SIDE = 'R'. If SIDE equals 'L', let C = [ C1 ] 1 [ C2 ] m-1 n Then C is overwritten by P*C. If SIDE equals 'R', let C = [ C1, C2 ] m 1 n-1 Then C is overwritten by C*P.

**ARGUMENTS**

SIDE (input) CHARACTER*1 = 'L': form P * C = 'R': 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 = 'L' (1 + (N-1)*abs(INCV)) if SIDE = 'R' 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 = 'L' (M,1) if SIDE = 'R' On entry, the n-vector C1 if SIDE = 'L', or the m-vector C1 if SIDE = 'R'. On exit, the first row of P*C if SIDE = 'L', or the first column of C*P if SIDE = 'R'. C2 (input/output) DOUBLE PRECISION array, dimension (LDC, N) if SIDE = 'L' (LDC, N-1) if SIDE = 'R' On entry, the (m - 1) x n matrix C2 if SIDE = 'L', or the m x (n - 1) matrix C2 if SIDE = 'R'. On exit, rows 2:m of P*C if SIDE = 'L', or columns 2:m of C*P if SIDE = 'R'. LDC (input) INTEGER The leading dimension of the arrays C1 and C2. LDC >= (1,M). WORK (workspace) DOUBLE PRECISION array, dimension (N) if SIDE = 'L' (M) if SIDE = 'R' LAPACK routine (version 3.3.1) April 2011 DLATZM(3lapack)