.TH "sgelq2.f" 3 "Sun May 26 2013" "Version 3.4.1" "LAPACK" \" -*- nroff -*- .ad l .nh .SH NAME sgelq2.f \- .SH SYNOPSIS .br .PP .SS "Functions/Subroutines" .in +1c .ti -1c .RI "subroutine \fBsgelq2\fP (M, N, A, LDA, TAU, WORK, INFO)" .br .RI "\fI\fBSGELQ2\fP \fP" .in -1c .SH "Function/Subroutine Documentation" .PP .SS "subroutine sgelq2 (integerM, integerN, real, dimension( lda, * )A, integerLDA, real, dimension( * )TAU, real, dimension( * )WORK, integerINFO)" .PP \fBSGELQ2\fP .PP \fBPurpose: \fP .RS 4 .PP .nf SGELQ2 computes an LQ factorization of a real m by n matrix A: A = L * Q. .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 REAL 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 orthogonal 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 REAL array, dimension (min(M,N)) The scalar factors of the elementary reflectors (see Further Details). .fi .PP .br \fIWORK\fP .PP .nf WORK is REAL 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 \fBDate:\fP .RS 4 November 2011 .RE .PP \fBFurther Details: \fP .RS 4 .PP .nf The matrix Q is represented as a product of elementary reflectors Q = H(k) . . . H(2) H(1), where k = min(m,n). Each H(i) has the form H(i) = I - tau * v * v**T where tau is a real scalar, and v is a real vector with v(1:i-1) = 0 and v(i) = 1; 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 122 of file sgelq2\&.f\&. .SH "Author" .PP Generated automatically by Doxygen for LAPACK from the source code\&.