All Packages Class Hierarchy This Package Previous Next Index
java.lang.Object | +----org.netlib.lapack.DGBBRD
DGBBRD is a simplified interface to the JLAPACK routine dgbbrd. 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 * ======= * * 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) 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) 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 * reduction. * * LDAB (input) INTEGER * The leading dimension of the array A. LDAB >= KL+KU+1. * * D (output) DOUBLE PRECISION array, dimension (min(M,N)) * The diagonal elements of the bidiagonal matrix B. * * E (output) DOUBLE PRECISION array, dimension (min(M,N)-1) * The superdiagonal 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) INTEGER * 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) INTEGER * 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) INTEGER * 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) INTEGER * = 0: successful exit. * < 0: if INFO = -i, the i-th argument had an illegal value. * * ===================================================================== * * .. Parameters ..
DGBBRD()
DGBBRD(String, int, int, int, int, int, double[][], double[], double[], double[][], double[][], double[][], double[], intW)
DGBBRD
public DGBBRD()
DGBBRD
public static void DGBBRD(String vect,
int m,
int n,
int ncc,
int kl,
int ku,
double ab[][],
double d[],
double e[],
double q[][],
double pt[][],
double c[][],
double work[],
intW info)
All Packages Class Hierarchy This Package Previous Next Index