zgeqr2p - computes the QR factorization of a general rectangular matrix with non-negative diagonal elements using an unblocked algorithm.
SUBROUTINE ZGEQR2P(M, N, A, LDA, TAU, WORK, INFO) INTEGER INFO, LDA, M, N DOUBLE COMPLEX A(LDA,*), TAU(*), WORK(*) SUBROUTINE ZGEQR2P_64(M, N, A, LDA, TAU, WORK, INFO) INTEGER*8 INFO, LDA, M, N DOUBLE COMPLEX A(LDA,*), TAU(*), WORK(*) F95 INTERFACE SUBROUTINE GEQR2P(M, N, A, LDA, TAU, WORK, INFO) INTEGER :: M, N, LDA, INFO COMPLEX(8), DIMENSION(:) :: TAU, WORK COMPLEX(8), DIMENSION(:,:) :: A SUBROUTINE GEQR2P_64(M, N, A, LDA, TAU, WORK, INFO) INTEGER(8) :: M, N, LDA, INFO COMPLEX(8), DIMENSION(:) :: TAU, WORK COMPLEX(8), DIMENSION(:,:) :: A C INTERFACE #include <sunperf.h> void zgeqr2p (int m, int n, doublecomplex *a, int lda, doublecomplex *tau, int *info); void zgeqr2p_64 (long m, long n, doublecomplex *a, long lda, doublecom- plex *tau, long *info);
Oracle Solaris Studio Performance Library zgeqr2p(3P) NAME zgeqr2p - computes the QR factorization of a general rectangular matrix with non-negative diagonal elements using an unblocked algorithm. SYNOPSIS SUBROUTINE ZGEQR2P(M, N, A, LDA, TAU, WORK, INFO) INTEGER INFO, LDA, M, N DOUBLE COMPLEX A(LDA,*), TAU(*), WORK(*) SUBROUTINE ZGEQR2P_64(M, N, A, LDA, TAU, WORK, INFO) INTEGER*8 INFO, LDA, M, N DOUBLE COMPLEX A(LDA,*), TAU(*), WORK(*) F95 INTERFACE SUBROUTINE GEQR2P(M, N, A, LDA, TAU, WORK, INFO) INTEGER :: M, N, LDA, INFO COMPLEX(8), DIMENSION(:) :: TAU, WORK COMPLEX(8), DIMENSION(:,:) :: A SUBROUTINE GEQR2P_64(M, N, A, LDA, TAU, WORK, INFO) INTEGER(8) :: M, N, LDA, INFO COMPLEX(8), DIMENSION(:) :: TAU, WORK COMPLEX(8), DIMENSION(:,:) :: A C INTERFACE #include <sunperf.h> void zgeqr2p (int m, int n, doublecomplex *a, int lda, doublecomplex *tau, int *info); void zgeqr2p_64 (long m, long n, doublecomplex *a, long lda, doublecom- plex *tau, long *info); PURPOSE zgeqr2p computes a QR factorization of a complex m by n matrix A: A=Q*R. 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*16 array, dimension (LDA,N) On entry, the m by n matrix A. On exit, the elements on and above the diagonal of the array contain the min(m,n) by n upper trapezoidal matrix R (R is upper triangular if m >= n); the elements below 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*16 array, dimension (min(M,N)) The scalar factors of the elementary reflectors (see Further Details). WORK (output) WORK is COMPLEX*16 array, dimension (N) 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(1) H(2) . . . H(k), 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; v(i+1:m) is stored on exit in A(i+1:m,i), and tau in TAU(i). 7 Nov 2015 zgeqr2p(3P)