.TH "SRC/zgelqt3.f" 3 "Version 3.12.0" "LAPACK" \" -*- nroff -*- .ad l .nh .SH NAME SRC/zgelqt3.f .SH SYNOPSIS .br .PP .SS "Functions/Subroutines" .in +1c .ti -1c .RI "recursive subroutine \fBzgelqt3\fP (m, n, a, lda, t, ldt, info)" .br .RI "\fBZGELQT3\fP recursively computes a LQ factorization of a general real or complex matrix using the compact WY representation of Q\&. " .in -1c .SH "Function/Subroutine Documentation" .PP .SS "recursive subroutine zgelqt3 (integer m, integer n, complex*16, dimension( lda, * ) a, integer lda, complex*16, dimension( ldt, * ) t, integer ldt, integer info)" .PP \fBZGELQT3\fP recursively computes a LQ factorization of a general real or complex matrix using the compact WY representation of Q\&. .PP \fBPurpose:\fP .RS 4 .PP .nf !> !> ZGELQT3 recursively computes a LQ factorization of a complex M-by-N !> matrix A, using the compact WY representation of Q\&. !> !> Based on the algorithm of Elmroth and Gustavson, !> IBM J\&. Res\&. Develop\&. Vol 44 No\&. 4 July 2000\&. !> .fi .PP .RE .PP \fBParameters\fP .RS 4 \fIM\fP .PP .nf !> M is INTEGER !> The number of rows of the matrix A\&. M =< N\&. !> .fi .PP .br \fIN\fP .PP .nf !> N is INTEGER !> The number of columns of the matrix A\&. N >= 0\&. !> .fi .PP .br \fIA\fP .PP .nf !> A is COMPLEX*16 array, dimension (LDA,N) !> On entry, the complex M-by-N matrix A\&. On exit, the elements on and !> below the diagonal contain the N-by-N lower triangular matrix L; the !> elements above the diagonal are the rows of V\&. See below for !> further details\&. !> .fi .PP .br \fILDA\fP .PP .nf !> LDA is INTEGER !> The leading dimension of the array A\&. LDA >= max(1,M)\&. !> .fi .PP .br \fIT\fP .PP .nf !> T is COMPLEX*16 array, dimension (LDT,N) !> The N-by-N upper triangular factor of the block reflector\&. !> The elements on and above the diagonal contain the block !> reflector T; the elements below the diagonal are not used\&. !> See below for further details\&. !> .fi .PP .br \fILDT\fP .PP .nf !> LDT is INTEGER !> The leading dimension of the array T\&. LDT >= max(1,N)\&. !> .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 \fBFurther Details:\fP .RS 4 .PP .nf !> !> The matrix V stores the elementary reflectors H(i) in the i-th row !> above the diagonal\&. For example, if M=5 and N=3, the matrix V is !> !> V = ( 1 v1 v1 v1 v1 ) !> ( 1 v2 v2 v2 ) !> ( 1 v3 v3 v3 ) !> !> !> where the vi's represent the vectors which define H(i), which are returned !> in the matrix A\&. The 1's along the diagonal of V are not stored in A\&. The !> block reflector H is then given by !> !> H = I - V * T * V**T !> !> where V**T is the transpose of V\&. !> !> For details of the algorithm, see Elmroth and Gustavson (cited above)\&. !> .fi .PP .RE .PP .PP Definition at line \fB130\fP of file \fBzgelqt3\&.f\fP\&. .SH "Author" .PP Generated automatically by Doxygen for LAPACK from the source code\&.