org.netlib.lapack
Class SGBBRD
java.lang.Object
org.netlib.lapack.SGBBRD
public class SGBBRD
- extends java.lang.Object
SGBBRD is a simplified interface to the JLAPACK routine sgbbrd.
This interface converts Java-style 2D row-major arrays into
the 1D column-major linearized arrays expected by the lower
level JLAPACK routines. Using this interface also allows you
to omit offset and leading dimension arguments. However, because
of these conversions, these routines will be slower than the low
level ones. Following is the description from the original Fortran
source. Contact seymour@cs.utk.edu with any questions.
* ..
*
* Purpose
* =======
*
* SGBBRD 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) CHARACTER*1
* 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) INTEGER
* The number of rows of the matrix A. M >= 0.
*
* N (input) INTEGER
* The number of columns of the matrix A. N >= 0.
*
* NCC (input) INTEGER
* The number of columns of the matrix C. NCC >= 0.
*
* KL (input) INTEGER
* The number of subdiagonals of the matrix A. KL >= 0.
*
* KU (input) INTEGER
* The number of superdiagonals of the matrix A. KU >= 0.
*
* AB (input/output) REAL 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
* reduction.
*
* LDAB (input) INTEGER
* The leading dimension of the array A. LDAB >= KL+KU+1.
*
* D (output) REAL array, dimension (min(M,N))
* The diagonal elements of the bidiagonal matrix B.
*
* E (output) REAL array, dimension (min(M,N)-1)
* The superdiagonal elements of the bidiagonal matrix B.
*
* Q (output) REAL 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) INTEGER
* The leading dimension of the array Q.
* LDQ >= max(1,M) if VECT = 'Q' or 'B'; LDQ >= 1 otherwise.
*
* PT (output) REAL 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) INTEGER
* The leading dimension of the array PT.
* LDPT >= max(1,N) if VECT = 'P' or 'B'; LDPT >= 1 otherwise.
*
* C (input/output) REAL 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) INTEGER
* The leading dimension of the array C.
* LDC >= max(1,M) if NCC > 0; LDC >= 1 if NCC = 0.
*
* WORK (workspace) REAL array, dimension (2*max(M,N))
*
* INFO (output) INTEGER
* = 0: successful exit.
* < 0: if INFO = -i, the i-th argument had an illegal value.
*
* =====================================================================
*
* .. Parameters ..
Method Summary |
static void |
SGBBRD(java.lang.String vect,
int m,
int n,
int ncc,
int kl,
int ku,
float[][] ab,
float[] d,
float[] e,
float[][] q,
float[][] pt,
float[][] c,
float[] work,
org.netlib.util.intW info)
|
Methods inherited from class java.lang.Object |
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait |
SGBBRD
public SGBBRD()
SGBBRD
public static void SGBBRD(java.lang.String vect,
int m,
int n,
int ncc,
int kl,
int ku,
float[][] ab,
float[] d,
float[] e,
float[][] q,
float[][] pt,
float[][] c,
float[] work,
org.netlib.util.intW info)