org.netlib.lapack
Class Dsysv
java.lang.Object
org.netlib.lapack.Dsysv
public class Dsysv
 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
* =======
*
* DSYSV computes the solution to a real system of linear equations
* A * X = B,
* where A is an NbyN symmetric matrix and X and B are NbyNRHS
* matrices.
*
* The diagonal pivoting method is used to factor A as
* A = U * D * U**T, if UPLO = 'U', or
* A = L * D * L**T, if UPLO = 'L',
* where U (or L) is a product of permutation and unit upper (lower)
* triangular matrices, and D is symmetric and block diagonal with
* 1by1 and 2by2 diagonal blocks. 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.
*
* A (input/output) DOUBLE PRECISION array, dimension (LDA,N)
* On entry, the symmetric matrix A. If UPLO = 'U', the leading
* NbyN upper triangular part of A contains the upper
* triangular part of the matrix A, and the strictly lower
* triangular part of A is not referenced. If UPLO = 'L', the
* leading NbyN lower triangular part of A contains the lower
* triangular part of the matrix A, and the strictly upper
* triangular part of A is not referenced.
*
* On exit, if INFO = 0, the block diagonal matrix D and the
* multipliers used to obtain the factor U or L from the
* factorization A = U*D*U**T or A = L*D*L**T as computed by
* DSYTRF.
*
* LDA (input) INTEGER
* The leading dimension of the array A. LDA >= max(1,N).
*
* IPIV (output) INTEGER array, dimension (N)
* Details of the interchanges and the block structure of D, as
* determined by DSYTRF. If IPIV(k) > 0, then rows and columns
* k and IPIV(k) were interchanged, and D(k,k) is a 1by1
* diagonal block. If UPLO = 'U' and IPIV(k) = IPIV(k1) < 0,
* then rows and columns k1 and IPIV(k) were interchanged and
* D(k1:k,k1:k) is a 2by2 diagonal block. If UPLO = 'L' and
* IPIV(k) = IPIV(k+1) < 0, then rows and columns k+1 and
* IPIV(k) were interchanged and D(k:k+1,k:k+1) is a 2by2
* diagonal block.
*
* B (input/output) DOUBLE PRECISION array, dimension (LDB,NRHS)
* On entry, the NbyNRHS right hand side matrix B.
* On exit, if INFO = 0, the NbyNRHS solution matrix X.
*
* LDB (input) INTEGER
* The leading dimension of the array B. LDB >= max(1,N).
*
* WORK (workspace/output) DOUBLE PRECISION array, dimension (LWORK)
* On exit, if INFO = 0, WORK(1) returns the optimal LWORK.
*
* LWORK (input) INTEGER
* The length of WORK. LWORK >= 1, and for best performance
* LWORK >= N*NB, where NB is the optimal blocksize for
* DSYTRF.
*
* If LWORK = 1, then a workspace query is assumed; the routine
* only calculates the optimal size of the WORK array, returns
* this value as the first entry of the WORK array, and no error
* message related to LWORK is issued by XERBLA.
*
* INFO (output) INTEGER
* = 0: successful exit
* < 0: if INFO = i, the ith argument had an illegal value
* > 0: if INFO = i, D(i,i) is exactly zero. The factorization
* has been completed, but the block diagonal matrix D is
* exactly singular, so the solution could not be computed.
*
* =====================================================================
*
* .. Local Scalars ..
Constructor Summary 
Dsysv()

Method Summary 
static void 
dsysv(java.lang.String uplo,
int n,
int nrhs,
double[] a,
int _a_offset,
int lda,
int[] ipiv,
int _ipiv_offset,
double[] b,
int _b_offset,
int ldb,
double[] work,
int _work_offset,
int lwork,
intW info)

Methods inherited from class java.lang.Object 
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait 
Dsysv
public Dsysv()
dsysv
public static void dsysv(java.lang.String uplo,
int n,
int nrhs,
double[] a,
int _a_offset,
int lda,
int[] ipiv,
int _ipiv_offset,
double[] b,
int _b_offset,
int ldb,
double[] work,
int _work_offset,
int lwork,
intW info)