cgelq2 - compute the LQ factorization of a general rectangular matrix using an unblocked algorithm
SUBROUTINE CGELQ2(M, N, A, LDA, TAU, WORK, INFO) INTEGER INFO, LDA, M, N COMPLEX A(LDA,*), TAU(*), WORK(*) SUBROUTINE CGELQ2_64(M, N, A, LDA, TAU, WORK, INFO) INTEGER*8 INFO, LDA, M, N COMPLEX A(LDA,*), TAU(*), WORK(*) F95 INTERFACE SUBROUTINE GELQ2(M, N, A, LDA, TAU, WORK, INFO) INTEGER :: M, N, LDA, INFO COMPLEX, DIMENSION(:) :: TAU, WORK COMPLEX, DIMENSION(:,:) :: A SUBROUTINE GELQ2_64(M, N, A, LDA, TAU, WORK, INFO) INTEGER(8) :: M, N, LDA, INFO COMPLEX, DIMENSION(:) :: TAU, WORK COMPLEX, DIMENSION(:,:) :: A C INTERFACE #include <sunperf.h> void cgelq2 (int m, int n, floatcomplex *a, int lda, floatcomplex *tau, int *info); void cgelq2_64 (long m, long n, floatcomplex *a, long lda, floatcomplex *tau, long *info);
Oracle Solaris Studio Performance Library cgelq2(3P) NAME cgelq2 - compute the LQ factorization of a general rectangular matrix using an unblocked algorithm SYNOPSIS SUBROUTINE CGELQ2(M, N, A, LDA, TAU, WORK, INFO) INTEGER INFO, LDA, M, N COMPLEX A(LDA,*), TAU(*), WORK(*) SUBROUTINE CGELQ2_64(M, N, A, LDA, TAU, WORK, INFO) INTEGER*8 INFO, LDA, M, N COMPLEX A(LDA,*), TAU(*), WORK(*) F95 INTERFACE SUBROUTINE GELQ2(M, N, A, LDA, TAU, WORK, INFO) INTEGER :: M, N, LDA, INFO COMPLEX, DIMENSION(:) :: TAU, WORK COMPLEX, DIMENSION(:,:) :: A SUBROUTINE GELQ2_64(M, N, A, LDA, TAU, WORK, INFO) INTEGER(8) :: M, N, LDA, INFO COMPLEX, DIMENSION(:) :: TAU, WORK COMPLEX, DIMENSION(:,:) :: A C INTERFACE #include <sunperf.h> void cgelq2 (int m, int n, floatcomplex *a, int lda, floatcomplex *tau, int *info); void cgelq2_64 (long m, long n, floatcomplex *a, long lda, floatcomplex *tau, long *info); PURPOSE cgelq2 computes an LQ factorization of a complex m by n matrix A: A=L*Q. 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. A (input/output) A is COMPLEX 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 prod- uct of elementary reflectors (see Further Details). LDA (input) LDA is INTEGER The leading dimension of the array A. LDA >= max(1,M). TAU (output) TAU is COMPLEX array, dimension (min(M,N)) The scalar factors of the elementary reflectors (see Further Details). WORK (output) WORK is COMPLEX array, dimension (M) INFO (output) INFO is INTEGER = 0: successful exit, < 0: if INFO = -i, the i-th argument had an illegal value. FURTHER DETAILS 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). 7 Nov 2015 cgelq2(3P)