LAPACK  3.4.2
LAPACK: Linear Algebra PACKage
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dlatzm.f File Reference

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Functions/Subroutines

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

Function/Subroutine Documentation

subroutine dlatzm ( character  SIDE,
integer  M,
integer  N,
double precision, dimension( * )  V,
integer  INCV,
double precision  TAU,
double precision, dimension( ldc, * )  C1,
double precision, dimension( ldc, * )  C2,
integer  LDC,
double precision, dimension( * )  WORK 
)

DLATZM

Download DLATZM + dependencies [TGZ] [ZIP] [TXT]
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 This routine is deprecated and has been replaced by routine DORMRZ.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.
Parameters
[in]SIDE
          SIDE is CHARACTER*1
          = 'L': form P * C
          = 'R': form C * P
[in]M
          M is INTEGER
          The number of rows of the matrix C.
[in]N
          N is INTEGER
          The number of columns of the matrix C.
[in]V
          V is 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.
[in]INCV
          INCV is INTEGER
          The increment between elements of v. INCV <> 0
[in]TAU
          TAU is DOUBLE PRECISION
          The value tau in the representation of P.
[in,out]C1
          C1 is 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'.
[in,out]C2
          C2 is 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'.
[in]LDC
          LDC is INTEGER
          The leading dimension of the arrays C1 and C2. LDC >= (1,M).
[out]WORK
          WORK is DOUBLE PRECISION array, dimension
                      (N) if SIDE = 'L'
                      (M) if SIDE = 'R'
Author
Univ. of Tennessee
Univ. of California Berkeley
Univ. of Colorado Denver
NAG Ltd.
Date
November 2011

Definition at line 152 of file dlatzm.f.

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