.TH "SRC/zupgtr.f" 3 "Version 3.12.0" "LAPACK" \" -*- nroff -*- .ad l .nh .SH NAME SRC/zupgtr.f .SH SYNOPSIS .br .PP .SS "Functions/Subroutines" .in +1c .ti -1c .RI "subroutine \fBzupgtr\fP (uplo, n, ap, tau, q, ldq, work, info)" .br .RI "\fBZUPGTR\fP " .in -1c .SH "Function/Subroutine Documentation" .PP .SS "subroutine zupgtr (character uplo, integer n, complex*16, dimension( * ) ap, complex*16, dimension( * ) tau, complex*16, dimension( ldq, * ) q, integer ldq, complex*16, dimension( * ) work, integer info)" .PP \fBZUPGTR\fP .PP \fBPurpose:\fP .RS 4 .PP .nf !> !> ZUPGTR generates a complex unitary matrix Q which is defined as the !> product of n-1 elementary reflectors H(i) of order n, as returned by !> ZHPTRD using packed storage: !> !> if UPLO = 'U', Q = H(n-1) \&. \&. \&. H(2) H(1), !> !> if UPLO = 'L', Q = H(1) H(2) \&. \&. \&. H(n-1)\&. !> .fi .PP .RE .PP \fBParameters\fP .RS 4 \fIUPLO\fP .PP .nf !> UPLO is CHARACTER*1 !> = 'U': Upper triangular packed storage used in previous !> call to ZHPTRD; !> = 'L': Lower triangular packed storage used in previous !> call to ZHPTRD\&. !> .fi .PP .br \fIN\fP .PP .nf !> N is INTEGER !> The order of the matrix Q\&. N >= 0\&. !> .fi .PP .br \fIAP\fP .PP .nf !> AP is COMPLEX*16 array, dimension (N*(N+1)/2) !> The vectors which define the elementary reflectors, as !> returned by ZHPTRD\&. !> .fi .PP .br \fITAU\fP .PP .nf !> TAU is COMPLEX*16 array, dimension (N-1) !> TAU(i) must contain the scalar factor of the elementary !> reflector H(i), as returned by ZHPTRD\&. !> .fi .PP .br \fIQ\fP .PP .nf !> Q is COMPLEX*16 array, dimension (LDQ,N) !> The N-by-N unitary matrix Q\&. !> .fi .PP .br \fILDQ\fP .PP .nf !> LDQ is INTEGER !> The leading dimension of the array Q\&. LDQ >= max(1,N)\&. !> .fi .PP .br \fIWORK\fP .PP .nf !> WORK is COMPLEX*16 array, dimension (N-1) !> .fi .PP .br \fIINFO\fP .PP .nf !> INFO is INTEGER !> = 0: successful exit !> < 0: if INFO = -i, the i-th argument had an illegal value !> .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 \fB113\fP of file \fBzupgtr\&.f\fP\&. .SH "Author" .PP Generated automatically by Doxygen for LAPACK from the source code\&.