.TH "sgeqrt2.f" 3 "Wed Oct 15 2014" "Version 3.4.2" "LAPACK" \" -*- nroff -*- .ad l .nh .SH NAME sgeqrt2.f \- .SH SYNOPSIS .br .PP .SS "Functions/Subroutines" .in +1c .ti -1c .RI "subroutine \fBsgeqrt2\fP (M, N, A, LDA, T, LDT, INFO)" .br .RI "\fI\fBSGEQRT2\fP computes a QR factorization of a general real or complex matrix using the compact WY representation of Q\&. \fP" .in -1c .SH "Function/Subroutine Documentation" .PP .SS "subroutine sgeqrt2 (integerM, integerN, real, dimension( lda, * )A, integerLDA, real, dimension( ldt, * )T, integerLDT, integerINFO)" .PP \fBSGEQRT2\fP computes a QR factorization of a general real or complex matrix using the compact WY representation of Q\&. .PP \fBPurpose: \fP .RS 4 .PP .nf SGEQRT2 computes a QR factorization of a real M-by-N matrix A, using the compact WY representation of 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 >= 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 REAL array, dimension (LDA,N) On entry, the real M-by-N matrix A. On exit, the elements on and above the diagonal contain the N-by-N upper triangular matrix R; the elements below the diagonal are the columns 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 REAL 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 \fBDate:\fP .RS 4 September 2012 .RE .PP \fBFurther Details: \fP .RS 4 .PP .nf The matrix V stores the elementary reflectors H(i) in the i-th column below the diagonal. For example, if M=5 and N=3, the matrix V is V = ( 1 ) ( v1 1 ) ( v1 v2 1 ) ( v1 v2 v3 ) ( v1 v2 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. .fi .PP .RE .PP .PP Definition at line 128 of file sgeqrt2\&.f\&. .SH "Author" .PP Generated automatically by Doxygen for LAPACK from the source code\&.