org.netlib.lapack
Class Sppsv

java.lang.Object
  org.netlib.lapack.Sppsv

public class Sppsv
extends java.lang.Object

Following is the description from the original
Fortran source.  For each array argument, the Java
version will include an integer offset parameter, so
the arguments may not match the description exactly.
Contact seymour@cs.utk.edu with any questions.


 *     ..
 *
 *  Purpose
 *  =======
 *
 *  SPPSV computes the solution to a real system of linear equations
 *     A * X = B,
 *  where A is an N-by-N symmetric positive definite matrix stored in
 *  packed format and X and B are N-by-NRHS matrices.
 *
 *  The Cholesky decomposition is used to factor A as
 *     A = U**T* U,  if UPLO = 'U', or
 *     A = L * L**T,  if UPLO = 'L',
 *  where U is an upper triangular matrix and L is a lower triangular
 *  matrix.  The factored form of A is then used to solve the system of
 *  equations A * X = B.
 *
 *  Arguments
 *  =========
 *
 *  UPLO    (input) CHARACTER*1
 *          = 'U':  Upper triangle of A is stored;
 *          = 'L':  Lower triangle of A is stored.
 *
 *  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.
 *
 *  AP      (input/output) REAL array, dimension (N*(N+1)/2)
 *          On entry, the upper or lower triangle of the symmetric matrix
 *          A, packed columnwise in a linear array.  The j-th column of A
 *          is stored in the array AP as follows:
 *          if UPLO = 'U', AP(i + (j-1)*j/2) = A(i,j) for 1<=i<=j;
 *          if UPLO = 'L', AP(i + (j-1)*(2n-j)/2) = A(i,j) for j<=i<=n.
 *          See below for further details.  
 *
 *          On exit, if INFO = 0, the factor U or L from the Cholesky
 *          factorization A = U**T*U or A = L*L**T, in the same storage
 *          format as A.
 *
 *  B       (input/output) REAL array, dimension (LDB,NRHS)
 *          On entry, the N-by-NRHS 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, the leading minor of order i of A is not
 *                positive definite, so the factorization could not be
 *                completed, and the solution has not been computed.
 *
 *  Further Details
 *  ===============
 *
 *  The packed storage scheme is illustrated by the following example
 *  when N = 4, UPLO = 'U':
 *
 *  Two-dimensional storage of the symmetric matrix A:
 *
 *     a11 a12 a13 a14
 *         a22 a23 a24
 *             a33 a34     (aij = conjg(aji))
 *                 a44
 *
 *  Packed storage of the upper triangle of A:
 *
 *  AP = [ a11, a12, a22, a13, a23, a33, a14, a24, a34, a44 ]
 *
 *  =====================================================================
 *
 *     .. External Functions ..

Constructor Summary

Sppsv()

Method Summary

static void

sppsv(java.lang.String uplo, int n, int nrhs, float[] ap, int _ap_offset, float[] b, int _b_offset, int ldb, intW info)

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

Sppsv

public Sppsv()

Method Detail

sppsv

public static void sppsv(java.lang.String uplo,
                         int n,
                         int nrhs,
                         float[] ap,
                         int _ap_offset,
                         float[] b,
                         int _b_offset,
                         int ldb,
                         intW info)