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

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subroutine zlarz (SIDE, M, N, L, V, INCV, TAU, C, LDC, WORK)
 ZLARZ applies an elementary reflector (as returned by stzrzf) to a general matrix.

Function/Subroutine Documentation

subroutine zlarz ( character  SIDE,
integer  M,
integer  N,
integer  L,
complex*16, dimension( * )  V,
integer  INCV,
complex*16  TAU,
complex*16, dimension( ldc, * )  C,
integer  LDC,
complex*16, dimension( * )  WORK 

ZLARZ applies an elementary reflector (as returned by stzrzf) to a general matrix.

Download ZLARZ + dependencies [TGZ] [ZIP] [TXT]
 ZLARZ applies a complex elementary reflector H to a complex
 M-by-N matrix C, from either the left or the right. H is represented
 in the form

       H = I - tau * v * v**H

 where tau is a complex scalar and v is a complex vector.

 If tau = 0, then H is taken to be the unit matrix.

 To apply H**H (the conjugate transpose of H), supply conjg(tau) instead

 H is a product of k elementary reflectors as returned by ZTZRZF.
          SIDE is CHARACTER*1
          = 'L': form  H * C
          = 'R': form  C * H
          M is INTEGER
          The number of rows of the matrix C.
          N is INTEGER
          The number of columns of the matrix C.
          L is INTEGER
          The number of entries of the vector V containing
          the meaningful part of the Householder vectors.
          If SIDE = 'L', M >= L >= 0, if SIDE = 'R', N >= L >= 0.
          V is COMPLEX*16 array, dimension (1+(L-1)*abs(INCV))
          The vector v in the representation of H as returned by
          ZTZRZF. V is not used if TAU = 0.
          INCV is INTEGER
          The increment between elements of v. INCV <> 0.
          TAU is COMPLEX*16
          The value tau in the representation of H.
          C is COMPLEX*16 array, dimension (LDC,N)
          On entry, the M-by-N matrix C.
          On exit, C is overwritten by the matrix H * C if SIDE = 'L',
          or C * H if SIDE = 'R'.
          LDC is INTEGER
          The leading dimension of the array C. LDC >= max(1,M).
          WORK is COMPLEX*16 array, dimension
                         (N) if SIDE = 'L'
                      or (M) if SIDE = 'R'
Univ. of Tennessee
Univ. of California Berkeley
Univ. of Colorado Denver
NAG Ltd.
September 2012
A. Petitet, Computer Science Dept., Univ. of Tenn., Knoxville, USA
Further Details:

Definition at line 148 of file zlarz.f.

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