dlatrz - factor an upper trapezoidal matrix by means of orthogonal transformations
SUBROUTINE DLATRZ( M, N, L, A, LDA, TAU, WORK ) INTEGER L, LDA, M, N DOUBLE PRECISION A(LDA,*), TAU(*),WORK(*) SUBROUTINE DLATRZ_64( M, N, L, A, LDA, TAU, WORK ) INTEGER*8 L, LDA, M, N DOUBLE PRECISION A(LDA,*), TAU(*),WORK(*) F95 INTERFACE SUBROUTINE LATRZ( M, N, L, A, LDA, TAU, WORK ) INTEGER :: M, N, L, LDA REAL(8), DIMENSION(:,:) :: A REAL(8), DIMENSION(:) :: TAU, WORK SUBROUTINE LATRZ_64( M, N, L, A, LDA, TAU, WORK ) INTEGER(8) :: M, N, L, LDA REAL(8), DIMENSION(:,:) :: A REAL(8), DIMENSION(:) :: TAU, WORK C INTERFACE #include <sunperf.h> void dlatrz (int m, int n, int l, double *a, int lda, double *tau); void dlatrz_64 (long m, long n, long l, double *a, long lda, double *tau);
Oracle Solaris Studio Performance Library dlatrz(3P) NAME dlatrz - factor an upper trapezoidal matrix by means of orthogonal transformations SYNOPSIS SUBROUTINE DLATRZ( M, N, L, A, LDA, TAU, WORK ) INTEGER L, LDA, M, N DOUBLE PRECISION A(LDA,*), TAU(*),WORK(*) SUBROUTINE DLATRZ_64( M, N, L, A, LDA, TAU, WORK ) INTEGER*8 L, LDA, M, N DOUBLE PRECISION A(LDA,*), TAU(*),WORK(*) F95 INTERFACE SUBROUTINE LATRZ( M, N, L, A, LDA, TAU, WORK ) INTEGER :: M, N, L, LDA REAL(8), DIMENSION(:,:) :: A REAL(8), DIMENSION(:) :: TAU, WORK SUBROUTINE LATRZ_64( M, N, L, A, LDA, TAU, WORK ) INTEGER(8) :: M, N, L, LDA REAL(8), DIMENSION(:,:) :: A REAL(8), DIMENSION(:) :: TAU, WORK C INTERFACE #include <sunperf.h> void dlatrz (int m, int n, int l, double *a, int lda, double *tau); void dlatrz_64 (long m, long n, long l, double *a, long lda, double *tau); PURPOSE dlatrz factors the M-by-(M+L) real upper trapezoidal matrix [ A1 A2 ] = [ A(1:M,1:M) A(1:M,N-L+1:N) ] as ( R 0 ) * Z, by means of orthogonal transformations. Z is an (M+L)-by-(M+L) orthogonal matrix and, R and A1 are M-by-M upper triangular matrices. ARGUMENTS M (input) M is INTEGER The number of rows of the matrix A. M >= 0. N (input) N is INTEGER The number of columns of the matrix A. N >= 0. L (input) L is INTEGER The number of columns of the matrix A containing the meaningful part of the Householder vectors. N-M >= L >= 0. A (input/output) A is DOUBLE PRECISION array, dimension (LDA,N) On entry, the leading M-by-N upper trapezoidal part of the array A must contain the matrix to be factorized. On exit, the leading M-by-M upper triangular part of A contains the upper triangular matrix R, and elements N-L+1 to N of the first M rows of A, with the array TAU, represent the orthogonal matrix Z as a product of M elementary reflectors. LDA (input) LDA is INTEGER The leading dimension of the array A. LDA >= max(1,M). TAU (output) TAU is DOUBLE PRECISION array, dimension (M) The scalar factors of the elementary reflectors. WORK (output) WORK is DOUBLE PRECISION array, dimension (M) 7 Nov 2015 dlatrz(3P)