dlarz - N matrix C, from either the left or the right
SUBROUTINE DLARZ(SIDE, M, N, L, V, INCV, TAU, C, LDC, WORK) CHARACTER*1 SIDE INTEGER M, N, L, INCV, LDC DOUBLE PRECISION TAU DOUBLE PRECISION V(*), C(LDC,*), WORK(*) SUBROUTINE DLARZ_64(SIDE, M, N, L, V, INCV, TAU, C, LDC, WORK) CHARACTER*1 SIDE INTEGER*8 M, N, L, INCV, LDC DOUBLE PRECISION TAU DOUBLE PRECISION V(*), C(LDC,*), WORK(*) F95 INTERFACE SUBROUTINE LARZ(SIDE, M, N, L, V, INCV, TAU, C, LDC, WORK) CHARACTER(LEN=1) :: SIDE INTEGER :: M, N, L, INCV, LDC REAL(8) :: TAU REAL(8), DIMENSION(:) :: V, WORK REAL(8), DIMENSION(:,:) :: C SUBROUTINE LARZ_64(SIDE, M, N, L, V, INCV, TAU, C, LDC, WORK) CHARACTER(LEN=1) :: SIDE INTEGER(8) :: M, N, L, INCV, LDC REAL(8) :: TAU REAL(8), DIMENSION(:) :: V, WORK REAL(8), DIMENSION(:,:) :: C C INTERFACE #include <sunperf.h> void dlarz(char side, int m, int n, int l, double *v, int incv, double tau, double *c, int ldc); void dlarz_64(char side, long m, long n, long l, double *v, long incv, double tau, double *c, long ldc);
Oracle Solaris Studio Performance Library dlarz(3P) NAME dlarz - apply a real elementary reflector H to a real M-by-N matrix C, from either the left or the right SYNOPSIS SUBROUTINE DLARZ(SIDE, M, N, L, V, INCV, TAU, C, LDC, WORK) CHARACTER*1 SIDE INTEGER M, N, L, INCV, LDC DOUBLE PRECISION TAU DOUBLE PRECISION V(*), C(LDC,*), WORK(*) SUBROUTINE DLARZ_64(SIDE, M, N, L, V, INCV, TAU, C, LDC, WORK) CHARACTER*1 SIDE INTEGER*8 M, N, L, INCV, LDC DOUBLE PRECISION TAU DOUBLE PRECISION V(*), C(LDC,*), WORK(*) F95 INTERFACE SUBROUTINE LARZ(SIDE, M, N, L, V, INCV, TAU, C, LDC, WORK) CHARACTER(LEN=1) :: SIDE INTEGER :: M, N, L, INCV, LDC REAL(8) :: TAU REAL(8), DIMENSION(:) :: V, WORK REAL(8), DIMENSION(:,:) :: C SUBROUTINE LARZ_64(SIDE, M, N, L, V, INCV, TAU, C, LDC, WORK) CHARACTER(LEN=1) :: SIDE INTEGER(8) :: M, N, L, INCV, LDC REAL(8) :: TAU REAL(8), DIMENSION(:) :: V, WORK REAL(8), DIMENSION(:,:) :: C C INTERFACE #include <sunperf.h> void dlarz(char side, int m, int n, int l, double *v, int incv, double tau, double *c, int ldc); void dlarz_64(char side, long m, long n, long l, double *v, long incv, double tau, double *c, long ldc); PURPOSE dlarz applies a real elementary reflector H to a real M-by-N matrix C, from either the left or the right. H is represented in the form H = I - tau * v * v' where tau is a real scalar and v is a real vector. If tau = 0, then H is taken to be the unit matrix. H is a product of k elementary reflectors as returned by DTZRZF. ARGUMENTS SIDE (input) = 'L': form H * C = 'R': form C * H M (input) The number of rows of the matrix C. N (input) The number of columns of the matrix C. L (input) The number of entries of the vector V containing the meaning- ful part of the Householder vectors. If SIDE = 'L', M >= L >= 0, if SIDE = 'R', N >= L >= 0. V (input) DOUBLE PRECISION array of dimension (1+(L-1)*abs(INCV)) The vector v in the representation of H as returned by DTZRZF. V is not used if TAU = 0. INCV (input) The increment between elements of v. INCV <> 0. TAU (input) The value tau in the representation of H. C (input/output) On entry, the M-by-N matrix C. On exit, C is overwritten by the matrix H * C if SIDE = 'L', or C * H if SIDE = 'R'. LDC (input) The leading dimension of the array C. LDC >= max(1,M). WORK (workspace) (N) if SIDE = 'L' or (M) if SIDE = 'R' FURTHER DETAILS Based on contributions by A. Petitet, Computer Science Dept., Univ. of Tenn., Knoxville, USA 7 Nov 2015 dlarz(3P)