Go to main content
Oracle Developer Studio 12.5 Man Pages

Exit Print View

Updated: June 2017
 
 

dgbbrd (3p)

Name

dgbbrd - n band matrix A to upper bidiagonal form B by an orthogonal transformation

Synopsis

SUBROUTINE DGBBRD(VECT, M, N, NCC, KL, KU, AB, LDAB, D, E, Q, LDQ,
PT, LDPT, C, LDC, WORK, INFO)

CHARACTER*1 VECT
INTEGER M, N, NCC, KL, KU, LDAB, LDQ, LDPT, LDC, INFO
DOUBLE  PRECISION  AB(LDAB,*),  D(*),   E(*),   Q(LDQ,*),   PT(LDPT,*),
C(LDC,*), WORK(*)

SUBROUTINE DGBBRD_64(VECT, M, N, NCC, KL, KU, AB, LDAB, D, E, Q, LDQ,
PT, LDPT, C, LDC, WORK, INFO)

CHARACTER*1 VECT
INTEGER*8 M, N, NCC, KL, KU, LDAB, LDQ, LDPT, LDC, INFO
DOUBLE   PRECISION   AB(LDAB,*),   D(*),  E(*),  Q(LDQ,*),  PT(LDPT,*),
C(LDC,*), WORK(*)




F95 INTERFACE
SUBROUTINE GBBRD(VECT, M, N, NCC, KL, KU, AB, LDAB, D, E, Q,
LDQ, PT, LDPT, C, LDC, WORK, INFO)

CHARACTER(LEN=1) :: VECT
INTEGER :: M, N, NCC, KL, KU, LDAB, LDQ, LDPT, LDC, INFO
REAL(8), DIMENSION(:) :: D, E, WORK
REAL(8), DIMENSION(:,:) :: AB, Q, PT, C

SUBROUTINE GBBRD_64(VECT, M, N, NCC, KL, KU, AB, LDAB, D, E,
Q, LDQ, PT, LDPT, C, LDC, WORK, INFO)

CHARACTER(LEN=1) :: VECT
INTEGER(8) :: M, N, NCC, KL, KU, LDAB, LDQ, LDPT, LDC, INFO
REAL(8), DIMENSION(:) :: D, E, WORK
REAL(8), DIMENSION(:,:) :: AB, Q, PT, C




C INTERFACE
#include <sunperf.h>

void dgbbrd(char vect, int m, int n, int ncc, int kl,  int  ku,  double
*ab, int ldab, double *d, double *e, double *q, int ldq, dou-
ble *pt, int ldpt, double *c, int ldc, int *info);

void dgbbrd_64(char vect, long m, long n, long ncc, long kl,  long  ku,
double  *ab, long ldab, double *d, double *e, double *q, long
ldq, double *pt, long ldpt, double *c, long ldc, long *info);

Description

Oracle Solaris Studio Performance Library                           dgbbrd(3P)



NAME
       dgbbrd - reduce a real general m-by-n band matrix A to upper bidiagonal
       form B by an orthogonal transformation


SYNOPSIS
       SUBROUTINE DGBBRD(VECT, M, N, NCC, KL, KU, AB, LDAB, D, E, Q, LDQ,
             PT, LDPT, C, LDC, WORK, INFO)

       CHARACTER*1 VECT
       INTEGER M, N, NCC, KL, KU, LDAB, LDQ, LDPT, LDC, INFO
       DOUBLE  PRECISION  AB(LDAB,*),  D(*),   E(*),   Q(LDQ,*),   PT(LDPT,*),
       C(LDC,*), WORK(*)

       SUBROUTINE DGBBRD_64(VECT, M, N, NCC, KL, KU, AB, LDAB, D, E, Q, LDQ,
             PT, LDPT, C, LDC, WORK, INFO)

       CHARACTER*1 VECT
       INTEGER*8 M, N, NCC, KL, KU, LDAB, LDQ, LDPT, LDC, INFO
       DOUBLE   PRECISION   AB(LDAB,*),   D(*),  E(*),  Q(LDQ,*),  PT(LDPT,*),
       C(LDC,*), WORK(*)




   F95 INTERFACE
       SUBROUTINE GBBRD(VECT, M, N, NCC, KL, KU, AB, LDAB, D, E, Q,
              LDQ, PT, LDPT, C, LDC, WORK, INFO)

       CHARACTER(LEN=1) :: VECT
       INTEGER :: M, N, NCC, KL, KU, LDAB, LDQ, LDPT, LDC, INFO
       REAL(8), DIMENSION(:) :: D, E, WORK
       REAL(8), DIMENSION(:,:) :: AB, Q, PT, C

       SUBROUTINE GBBRD_64(VECT, M, N, NCC, KL, KU, AB, LDAB, D, E,
              Q, LDQ, PT, LDPT, C, LDC, WORK, INFO)

       CHARACTER(LEN=1) :: VECT
       INTEGER(8) :: M, N, NCC, KL, KU, LDAB, LDQ, LDPT, LDC, INFO
       REAL(8), DIMENSION(:) :: D, E, WORK
       REAL(8), DIMENSION(:,:) :: AB, Q, PT, C




   C INTERFACE
       #include <sunperf.h>

       void dgbbrd(char vect, int m, int n, int ncc, int kl,  int  ku,  double
                 *ab, int ldab, double *d, double *e, double *q, int ldq, dou-
                 ble *pt, int ldpt, double *c, int ldc, int *info);

       void dgbbrd_64(char vect, long m, long n, long ncc, long kl,  long  ku,
                 double  *ab, long ldab, double *d, double *e, double *q, long
                 ldq, double *pt, long ldpt, double *c, long ldc, long *info);



PURPOSE
       dgbbrd  reduces a real general m-by-n band matrix A to upper bidiagonal
       form B by an orthogonal transformation: Q' * A * P = B.

       The routine computes B, and optionally forms Q or P', or computes  Q'*C
       for a given matrix C.


ARGUMENTS
       VECT (input)
                 Specifies  whether  or  not  the  matrices Q and P' are to be
                 formed.  = 'N': do not form Q or P';
                 = 'Q': form Q only;
                 = 'P': form P' only;
                 = 'B': form both.


       M (input) The number of rows of the matrix A.  M >= 0.


       N (input) The number of columns of the matrix A.  N >= 0.


       NCC (input)
                 The number of columns of the matrix C.  NCC >= 0.


       KL (input)
                 The number of subdiagonals of the matrix A. KL >= 0.


       KU (input)
                 The number of superdiagonals of the matrix A. KU >= 0.


       AB (input/output)
                 DOUBLE PRECISION array, dimension(LDAB,N) On entry, the m-by-
                 n band matrix A, stored in rows 1 to KL+KU+1. The j-th column
                 of A is stored in the j-th column of the array AB as follows:
                 AB(ku+1+i-j,j)  = A(i,j) for max(1,j-ku)<=i<=min(m,j+kl).  On
                 exit, A is overwritten by values generated during the  reduc-
                 tion.


       LDAB (input)
                 The leading dimension of the array A. LDAB >= KL+KU+1.


       D (output)
                 DOUBLE PRECISION array, dimension(min(M,N)) The diagonal ele-
                 ments of the bidiagonal matrix B.


       E (output)
                 DOUBLE PRECISION array, dimension(min(M,N)-1) The superdiago-
                 nal elements of the bidiagonal matrix B.


       Q (output)
                 DOUBLE  PRECISION  array,  dimension(LDQ,M)  If VECT = 'Q' or
                 'B', the m-by-m orthogonal matrix Q.  If VECT = 'N'  or  'P',
                 the array Q is not referenced.


       LDQ (input)
                 The  leading  dimension  of  the array Q.  LDQ >= max(1,M) if
                 VECT = 'Q' or 'B'; LDQ >= 1 otherwise.


       PT (output)
                 DOUBLE PRECISION array, dimension(LDPT,N) If VECT  =  'P'  or
                 'B',  the n-by-n orthogonal matrix P'.  If VECT = 'N' or 'Q',
                 the array PT is not referenced.


       LDPT (input)
                 The leading dimension of the array PT.  LDPT >=  max(1,N)  if
                 VECT = 'P' or 'B'; LDPT >= 1 otherwise.


       C (input/output)
                 DOUBLE PRECISION array, dimension(LDC,NCC) On entry, an m-by-
                 ncc matrix C.  On exit, C is overwritten by Q'*C.  C  is  not
                 referenced if NCC = 0.


       LDC (input)
                 The leading dimension of the array C.  LDC >= max(1,M) if NCC
                 > 0; LDC >= 1 if NCC = 0.


       WORK (workspace)
                 DOUBLE PRECISION array, dimension(2*MAX(M,N))

       INFO (output)
                 = 0:  successful exit;
                 < 0:  if INFO = -i, the i-th argument had an illegal value.




                                  7 Nov 2015                        dgbbrd(3P)