All Packages  Class Hierarchy  This Package  Previous  Next  Index

Class org.netlib.lapack.DGETRF

java.lang.Object
   |
   +----org.netlib.lapack.DGETRF

public class DGETRF

extends Object

DGETRF is a simplified interface to the JLAPACK routine dgetrf.
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
 *  =======
 *
 *  DGETRF computes an LU factorization of a general M-by-N matrix A
 *  using partial pivoting with row interchanges.
 *
 *  The factorization has the form
 *     A = P * L * U
 *  where P is a permutation matrix, L is lower triangular with unit
 *  diagonal elements (lower trapezoidal if m > n), and U is upper
 *  triangular (upper trapezoidal if m < n).
 *
 *  This is the right-looking Level 3 BLAS version of the algorithm.
 *
 *  Arguments
 *  =========
 *
 *  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.
 *
 *  A       (input/output) DOUBLE PRECISION array, dimension (LDA,N)
 *          On entry, the M-by-N matrix to be factored.
 *          On exit, the factors L and U from the factorization
 *          A = P*L*U; the unit diagonal elements of L are not stored.
 *
 *  LDA     (input) INTEGER
 *          The leading dimension of the array A.  LDA >= max(1,M).
 *
 *  IPIV    (output) INTEGER array, dimension (min(M,N))
 *          The pivot indices; for 1 <= i <= min(M,N), row i of the
 *          matrix was interchanged with row IPIV(i).
 *
 *  INFO    (output) INTEGER
 *          = 0:  successful exit
 *          < 0:  if INFO = -i, the i-th argument had an illegal value
 *          > 0:  if INFO = i, U(i,i) is exactly zero. The factorization
 *                has been completed, but the factor U is exactly
 *                singular, and division by zero will occur if it is used
 *                to solve a system of equations.
 *
 *  =====================================================================
 *
 *     .. Parameters ..

DGETRF()

DGETRF(int, int, double[][], int[], intW)

 public DGETRF()

 public static void DGETRF(int m,
                           int n,
                           double a[][],
                           int ipiv[],
                           intW info)

All Packages  Class Hierarchy  This Package  Previous  Next  Index