.TH "SRC/slarfgp.f" 3 "Version 3.12.0" "LAPACK" \" -*- nroff -*- .ad l .nh .SH NAME SRC/slarfgp.f .SH SYNOPSIS .br .PP .SS "Functions/Subroutines" .in +1c .ti -1c .RI "subroutine \fBslarfgp\fP (n, alpha, x, incx, tau)" .br .RI "\fBSLARFGP\fP generates an elementary reflector (Householder matrix) with non-negative beta\&. " .in -1c .SH "Function/Subroutine Documentation" .PP .SS "subroutine slarfgp (integer n, real alpha, real, dimension( * ) x, integer incx, real tau)" .PP \fBSLARFGP\fP generates an elementary reflector (Householder matrix) with non-negative beta\&. .PP \fBPurpose:\fP .RS 4 .PP .nf !> !> SLARFGP generates a real elementary reflector H of order n, such !> that !> !> H * ( alpha ) = ( beta ), H**T * H = I\&. !> ( x ) ( 0 ) !> !> where alpha and beta are scalars, beta is non-negative, and x is !> an (n-1)-element real vector\&. H is represented in the form !> !> H = I - tau * ( 1 ) * ( 1 v**T ) , !> ( v ) !> !> where tau is a real scalar and v is a real (n-1)-element !> vector\&. !> !> If the elements of x are all zero, then tau = 0 and H is taken to be !> the unit matrix\&. !> .fi .PP .RE .PP \fBParameters\fP .RS 4 \fIN\fP .PP .nf !> N is INTEGER !> The order of the elementary reflector\&. !> .fi .PP .br \fIALPHA\fP .PP .nf !> ALPHA is REAL !> On entry, the value alpha\&. !> On exit, it is overwritten with the value beta\&. !> .fi .PP .br \fIX\fP .PP .nf !> X is REAL array, dimension !> (1+(N-2)*abs(INCX)) !> On entry, the vector x\&. !> On exit, it is overwritten with the vector v\&. !> .fi .PP .br \fIINCX\fP .PP .nf !> INCX is INTEGER !> The increment between elements of X\&. INCX > 0\&. !> .fi .PP .br \fITAU\fP .PP .nf !> TAU is REAL !> The value tau\&. !> .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 \fB103\fP of file \fBslarfgp\&.f\fP\&. .SH "Author" .PP Generated automatically by Doxygen for LAPACK from the source code\&.