dlarfy.f3
Usage
Functions/Subroutines
subroutine dlarfy (uplo, n, v, incv, tau, c, ldc, work)
DLARFY
Function/Subroutine Documentation
subroutine dlarfy (character uplo, integer n, double precision, dimension( * ) v, integer incv, double precision tau, double precision, dimension( ldc, * ) c, integer ldc, double precision, dimension( * ) work)
DLARFY
Purpose:
!> !> DLARFY applies an elementary reflector, or Householder matrix, H, !> to an n x n symmetric matrix C, from both the left and the right. !> !> H is represented in the form !> !> H = I - tau * v * v' !> !> where tau is a scalar and v is a vector. !> !> If tau is zero, then H is taken to be the unit matrix. !>
Parameters
UPLO
!> UPLO is CHARACTER*1 !> Specifies whether the upper or lower triangular part of the !> symmetric matrix C is stored. !> = 'U': Upper triangle !> = 'L': Lower triangle !>
N
!> N is INTEGER !> The number of rows and columns of the matrix C. N >= 0. !>
V
!> V is DOUBLE PRECISION array, dimension !> (1 + (N-1)*abs(INCV)) !> The vector v as described above. !>
INCV
!> INCV is INTEGER !> The increment between successive elements of v. INCV must !> not be zero. !>
TAU
!> TAU is DOUBLE PRECISION !> The value tau as described above. !>
C
!> C is DOUBLE PRECISION array, dimension (LDC, N) !> On entry, the matrix C. !> On exit, C is overwritten by H * C * H'. !>
LDC
!> LDC is INTEGER !> The leading dimension of the array C. LDC >= max( 1, N ). !>
WORK
!> WORK is DOUBLE PRECISION array, dimension (N) !>
Author
Univ. of Tennessee
Univ. of California Berkeley
Univ. of Colorado Denver
NAG Ltd.
Definition at line 107 of file dlarfy.f.
Releases
2 releases since Debian 9 (Stretch); the text changed 1 time.