.TH "SRC/zgelq2.f" 3 "Version 3.12.0" "LAPACK" \" -*- nroff -*- .ad l .nh .SH NAME SRC/zgelq2.f .SH SYNOPSIS .br .PP .SS "Functions/Subroutines" .in +1c .ti -1c .RI "subroutine \fBzgelq2\fP (m, n, a, lda, tau, work, info)" .br .RI "\fBZGELQ2\fP computes the LQ factorization of a general rectangular matrix using an unblocked algorithm\&. " .in -1c .SH "Function/Subroutine Documentation" .PP .SS "subroutine zgelq2 (integer m, integer n, complex*16, dimension( lda, * ) a, integer lda, complex*16, dimension( * ) tau, complex*16, dimension( * ) work, integer info)" .PP \fBZGELQ2\fP computes the LQ factorization of a general rectangular matrix using an unblocked algorithm\&. .PP \fBPurpose:\fP .RS 4 .PP .nf !> !> ZGELQ2 computes an LQ factorization of a complex m-by-n matrix A: !> !> A = ( L 0 ) * Q !> !> where: !> !> Q is a n-by-n orthogonal matrix; !> L is a lower-triangular m-by-m matrix; !> 0 is a m-by-(n-m) zero matrix, if m < n\&. !> !> .fi .PP .RE .PP \fBParameters\fP .RS 4 \fIM\fP .PP .nf !> M is INTEGER !> The number of rows of the matrix A\&. M >= 0\&. !> .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 m by n matrix A\&. !> On exit, the elements on and below the diagonal of the array !> contain the m by min(m,n) lower trapezoidal matrix L (L is !> lower triangular if m <= n); the elements above the diagonal, !> with the array TAU, represent the unitary matrix Q as a !> product of elementary reflectors (see 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 \fITAU\fP .PP .nf !> TAU is COMPLEX*16 array, dimension (min(M,N)) !> The scalar factors of the elementary reflectors (see Further !> Details)\&. !> .fi .PP .br \fIWORK\fP .PP .nf !> WORK is COMPLEX*16 array, dimension (M) !> .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 Q is represented as a product of elementary reflectors !> !> Q = H(k)**H \&. \&. \&. H(2)**H H(1)**H, where k = min(m,n)\&. !> !> Each H(i) has the form !> !> H(i) = I - tau * v * v**H !> !> where tau is a complex scalar, and v is a complex vector with !> v(1:i-1) = 0 and v(i) = 1; conjg(v(i+1:n)) is stored on exit in !> A(i,i+1:n), and tau in TAU(i)\&. !> .fi .PP .RE .PP .PP Definition at line \fB128\fP of file \fBzgelq2\&.f\fP\&. .SH "Author" .PP Generated automatically by Doxygen for LAPACK from the source code\&.