.TH "SRC/zlarfg.f" 3 "Version 3.12.0" "LAPACK" \" -*- nroff -*- .ad l .nh .SH NAME SRC/zlarfg.f .SH SYNOPSIS .br .PP .SS "Functions/Subroutines" .in +1c .ti -1c .RI "subroutine \fBzlarfg\fP (n, alpha, x, incx, tau)" .br .RI "\fBZLARFG\fP generates an elementary reflector (Householder matrix)\&. " .in -1c .SH "Function/Subroutine Documentation" .PP .SS "subroutine zlarfg (integer n, complex*16 alpha, complex*16, dimension( * ) x, integer incx, complex*16 tau)" .PP \fBZLARFG\fP generates an elementary reflector (Householder matrix)\&. .PP \fBPurpose:\fP .RS 4 .PP .nf !> !> ZLARFG generates a complex elementary reflector H of order n, such !> that !> !> H**H * ( alpha ) = ( beta ), H**H * H = I\&. !> ( x ) ( 0 ) !> !> where alpha and beta are scalars, with beta real, and x is an !> (n-1)-element complex vector\&. H is represented in the form !> !> H = I - tau * ( 1 ) * ( 1 v**H ) , !> ( v ) !> !> where tau is a complex scalar and v is a complex (n-1)-element !> vector\&. Note that H is not hermitian\&. !> !> If the elements of x are all zero and alpha is real, then tau = 0 !> and H is taken to be the unit matrix\&. !> !> Otherwise 1 <= real(tau) <= 2 and abs(tau-1) <= 1 \&. !> .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 COMPLEX*16 !> On entry, the value alpha\&. !> On exit, it is overwritten with the value beta\&. !> .fi .PP .br \fIX\fP .PP .nf !> X is COMPLEX*16 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 COMPLEX*16 !> 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 \fB105\fP of file \fBzlarfg\&.f\fP\&. .SH "Author" .PP Generated automatically by Doxygen for LAPACK from the source code\&.