.TH "SRC/dlarz.f" 3 "Version 3.12.0" "LAPACK" \" -*- nroff -*- .ad l .nh .SH NAME SRC/dlarz.f .SH SYNOPSIS .br .PP .SS "Functions/Subroutines" .in +1c .ti -1c .RI "subroutine \fBdlarz\fP (side, m, n, l, v, incv, tau, c, ldc, work)" .br .RI "\fBDLARZ\fP applies an elementary reflector (as returned by stzrzf) to a general matrix\&. " .in -1c .SH "Function/Subroutine Documentation" .PP .SS "subroutine dlarz (character side, integer m, integer n, integer l, double precision, dimension( * ) v, integer incv, double precision tau, double precision, dimension( ldc, * ) c, integer ldc, double precision, dimension( * ) work)" .PP \fBDLARZ\fP applies an elementary reflector (as returned by stzrzf) to a general matrix\&. .PP \fBPurpose:\fP .RS 4 .PP .nf DLARZ applies a real elementary reflector H to a real M-by-N matrix C, from either the left or the right\&. H is represented in the form H = I - tau * v * v**T where tau is a real scalar and v is a real vector\&. If tau = 0, then H is taken to be the unit matrix\&. H is a product of k elementary reflectors as returned by DTZRZF\&. .fi .PP .RE .PP \fBParameters\fP .RS 4 \fISIDE\fP .PP .nf SIDE is CHARACTER*1 = 'L': form H * C = 'R': form C * H .fi .PP .br \fIM\fP .PP .nf M is INTEGER The number of rows of the matrix C\&. .fi .PP .br \fIN\fP .PP .nf N is INTEGER The number of columns of the matrix C\&. .fi .PP .br \fIL\fP .PP .nf 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\&. .fi .PP .br \fIV\fP .PP .nf V is DOUBLE PRECISION array, dimension (1+(L-1)*abs(INCV)) The vector v in the representation of H as returned by DTZRZF\&. V is not used if TAU = 0\&. .fi .PP .br \fIINCV\fP .PP .nf INCV is INTEGER The increment between elements of v\&. INCV <> 0\&. .fi .PP .br \fITAU\fP .PP .nf TAU is DOUBLE PRECISION The value tau in the representation of H\&. .fi .PP .br \fIC\fP .PP .nf C is DOUBLE PRECISION 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'\&. .fi .PP .br \fILDC\fP .PP .nf LDC is INTEGER The leading dimension of the array C\&. LDC >= max(1,M)\&. .fi .PP .br \fIWORK\fP .PP .nf WORK is DOUBLE PRECISION array, dimension (N) if SIDE = 'L' or (M) if SIDE = 'R' .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 \fBContributors:\fP .RS 4 A\&. Petitet, Computer Science Dept\&., Univ\&. of Tenn\&., Knoxville, USA .RE .PP \fBFurther Details:\fP .RS 4 .PP .nf .fi .PP .RE .PP .PP Definition at line \fB144\fP of file \fBdlarz\&.f\fP\&. .SH "Author" .PP Generated automatically by Doxygen for LAPACK from the source code\&.