All Packages  Class Hierarchy  This Package  Previous  Next  Index

Class org.netlib.lapack.DGESV

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

public class DGESV

extends Object

DGESV is a simplified interface to the JLAPACK routine dgesv.
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
 *  =======
 *
 *  DGESV computes the solution to a real system of linear equations
 *     A * X = B,
 *  where A is an N-by-N matrix and X and B are N-by-NRHS matrices.
 *
 *  The LU decomposition with partial pivoting and row interchanges is
 *  used to factor A as
 *     A = P * L * U,
 *  where P is a permutation matrix, L is unit lower triangular, and U is
 *  upper triangular.  The factored form of A is then used to solve the
 *  system of equations A * X = B.
 *
 *  Arguments
 *  =========
 *
 *  N       (input) INTEGER
 *          The number of linear equations, i.e., the order of the
 *          matrix A.  N >= 0.
 *
 *  NRHS    (input) INTEGER
 *          The number of right hand sides, i.e., the number of columns
 *          of the matrix B.  NRHS >= 0.
 *
 *  A       (input/output) DOUBLE PRECISION array, dimension (LDA,N)
 *          On entry, the N-by-N coefficient matrix A.
 *          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,N).
 *
 *  IPIV    (output) INTEGER array, dimension (N)
 *          The pivot indices that define the permutation matrix P;
 *          row i of the matrix was interchanged with row IPIV(i).
 *
 *  B       (input/output) DOUBLE PRECISION array, dimension (LDB,NRHS)
 *          On entry, the N-by-NRHS matrix of right hand side matrix B.
 *          On exit, if INFO = 0, the N-by-NRHS solution matrix X.
 *
 *  LDB     (input) INTEGER
 *          The leading dimension of the array B.  LDB >= max(1,N).
 *
 *  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, so the solution could not be computed.
 *
 *  =====================================================================
 *
 *     .. External Subroutines ..

DGESV()

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

 public DGESV()

 public static void DGESV(int n,
                          int nrhs,
                          double a[][],
                          int ipiv[],
                          double b[][],
                          intW info)

All Packages  Class Hierarchy  This Package  Previous  Next  Index