.TH "TESTING/EIG/dlarfy.f" 3 "Version 3.12.0" "LAPACK" \" -*- nroff -*- .ad l .nh .SH NAME TESTING/EIG/dlarfy.f .SH SYNOPSIS .br .PP .SS "Functions/Subroutines" .in +1c .ti -1c .RI "subroutine \fBdlarfy\fP (uplo, n, v, incv, tau, c, ldc, work)" .br .RI "\fBDLARFY\fP " .in -1c .SH "Function/Subroutine Documentation" .PP .SS "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)" .PP \fBDLARFY\fP .PP \fBPurpose:\fP .RS 4 .PP .nf 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\&. .fi .PP .RE .PP \fBParameters\fP .RS 4 \fIUPLO\fP .PP .nf 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 .fi .PP .br \fIN\fP .PP .nf N is INTEGER The number of rows and columns of the matrix C\&. N >= 0\&. .fi .PP .br \fIV\fP .PP .nf V is DOUBLE PRECISION array, dimension (1 + (N-1)*abs(INCV)) The vector v as described above\&. .fi .PP .br \fIINCV\fP .PP .nf INCV is INTEGER The increment between successive elements of v\&. INCV must not be zero\&. .fi .PP .br \fITAU\fP .PP .nf TAU is DOUBLE PRECISION The value tau as described above\&. .fi .PP .br \fIC\fP .PP .nf C is DOUBLE PRECISION array, dimension (LDC, N) On entry, the matrix C\&. On exit, C is overwritten by H * C * H'\&. .fi .PP .br \fILDC\fP .PP .nf LDC is INTEGER The leading dimension of the array C\&. LDC >= max( 1, N )\&. .fi .PP .br \fIWORK\fP .PP .nf WORK is DOUBLE PRECISION array, dimension (N) .fi .PP .RE .PP \fBAuthor\fP .RS 4 Univ\&. of Tennessee .PP Univ\&. of California Berkeley .PP Univ\&. of Colorado Denver .PP NAG Ltd\&. .RE .PP .PP Definition at line \fB107\fP of file \fBdlarfy\&.f\fP\&. .SH "Author" .PP Generated automatically by Doxygen for LAPACK from the source code\&.