.TH "slarfgp.f" 3 "Wed Oct 15 2014" "Version 3.4.2" "LAPACK" \" -*- nroff -*- .ad l .nh .SH NAME slarfgp.f \- .SH SYNOPSIS .br .PP .SS "Functions/Subroutines" .in +1c .ti -1c .RI "subroutine \fBslarfgp\fP (N, ALPHA, X, INCX, TAU)" .br .RI "\fI\fBSLARFGP\fP generates an elementary reflector (Householder matrix) with non-negatibe beta\&. \fP" .in -1c .SH "Function/Subroutine Documentation" .PP .SS "subroutine slarfgp (integerN, realALPHA, real, dimension( * )X, integerINCX, realTAU)" .PP \fBSLARFGP\fP generates an elementary reflector (Householder matrix) with non-negatibe 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 \fBDate:\fP .RS 4 September 2012 .RE .PP .PP Definition at line 105 of file slarfgp\&.f\&. .SH "Author" .PP Generated automatically by Doxygen for LAPACK from the source code\&.