dgbbrd
dgbbrd - reduce a real general m-by-n band matrix A to upper bidiagonal form B by an orthogonal transformation
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(*)
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
#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, double *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);
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.
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* VECT (input)
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Specifies whether or not the matrices Q and P' are to be
formed.
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* M (input)
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The number of rows of the matrix A. M >= 0.
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* N (input)
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The number of columns of the matrix A. N >= 0.
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* NCC (input)
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The number of columns of the matrix C. NCC >= 0.
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* KL (input)
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The number of subdiagonals of the matrix A. KL >= 0.
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* KU (input)
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The number of superdiagonals of the matrix A. KU >= 0.
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* AB (input/output)
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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
reduction.
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* LDAB (input)
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The leading dimension of the array A. LDAB >= KL+KU+1.
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* D (output)
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The diagonal elements of the bidiagonal matrix B.
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* E (output)
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The superdiagonal elements of the bidiagonal matrix B.
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* Q (output)
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If VECT = 'Q' or 'B', the m-by-m orthogonal matrix Q.
If VECT = 'N' or 'P', the array Q is not referenced.
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* LDQ (input)
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The leading dimension of the array Q.
LDQ >= max(1,M) if VECT = 'Q' or 'B'; LDQ >= 1 otherwise.
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* PT (output)
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If VECT = 'P' or 'B', the n-by-n orthogonal matrix P'.
If VECT = 'N' or 'Q', the array PT is not referenced.
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* LDPT (input)
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The leading dimension of the array PT.
LDPT >= max(1,N) if VECT = 'P' or 'B'; LDPT >= 1 otherwise.
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* C (input/output)
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On entry, an m-by-ncc matrix C.
On exit, C is overwritten by Q'*C.
C is not referenced if NCC = 0.
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* LDC (input)
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The leading dimension of the array C.
LDC >= max(1,M) if NCC > 0; LDC >= 1 if NCC = 0.
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* WORK (workspace)
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dimension(MAX(M,N))
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* INFO (output)
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