org.netlib.lapack
Class Sspgv
java.lang.Object
org.netlib.lapack.Sspgv
public class Sspgv
- 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
* =======
*
* SSPGV computes all the eigenvalues and, optionally, the eigenvectors
* of a real generalized symmetric-definite eigenproblem, of the form
* A*x=(lambda)*B*x, A*Bx=(lambda)*x, or B*A*x=(lambda)*x.
* Here A and B are assumed to be symmetric, stored in packed format,
* and B is also positive definite.
*
* Arguments
* =========
*
* ITYPE (input) INTEGER
* Specifies the problem type to be solved:
* = 1: A*x = (lambda)*B*x
* = 2: A*B*x = (lambda)*x
* = 3: B*A*x = (lambda)*x
*
* JOBZ (input) CHARACTER*1
* = 'N': Compute eigenvalues only;
* = 'V': Compute eigenvalues and eigenvectors.
*
* UPLO (input) CHARACTER*1
* = 'U': Upper triangles of A and B are stored;
* = 'L': Lower triangles of A and B are stored.
*
* N (input) INTEGER
* The order of the matrices A and B. N >= 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)*(2*n-j)/2) = A(i,j) for j<=i<=n.
*
* On exit, the contents of AP are destroyed.
*
* BP (input/output) REAL array, dimension (N*(N+1)/2)
* On entry, the upper or lower triangle of the symmetric matrix
* B, packed columnwise in a linear array. The j-th column of B
* is stored in the array BP as follows:
* if UPLO = 'U', BP(i + (j-1)*j/2) = B(i,j) for 1<=i<=j;
* if UPLO = 'L', BP(i + (j-1)*(2*n-j)/2) = B(i,j) for j<=i<=n.
*
* On exit, the triangular factor U or L from the Cholesky
* factorization B = U**T*U or B = L*L**T, in the same storage
* format as B.
*
* W (output) REAL array, dimension (N)
* If INFO = 0, the eigenvalues in ascending order.
*
* Z (output) REAL array, dimension (LDZ, N)
* If JOBZ = 'V', then if INFO = 0, Z contains the matrix Z of
* eigenvectors. The eigenvectors are normalized as follows:
* if ITYPE = 1 or 2, Z**T*B*Z = I;
* if ITYPE = 3, Z**T*inv(B)*Z = I.
* If JOBZ = 'N', then Z is not referenced.
*
* LDZ (input) INTEGER
* The leading dimension of the array Z. LDZ >= 1, and if
* JOBZ = 'V', LDZ >= max(1,N).
*
* WORK (workspace) REAL array, dimension (3*N)
*
* INFO (output) INTEGER
* = 0: successful exit
* < 0: if INFO = -i, the i-th argument had an illegal value
* > 0: SPPTRF or SSPEV returned an error code:
* <= N: if INFO = i, SSPEV failed to converge;
* i off-diagonal elements of an intermediate
* tridiagonal form did not converge to zero.
* > N: if INFO = n + i, for 1 <= i <= n, then the leading
* minor of order i of B is not positive definite.
* The factorization of B could not be completed and
* no eigenvalues or eigenvectors were computed.
*
* =====================================================================
*
* .. Local Scalars ..
|
Constructor Summary |
Sspgv()
|
|
Method Summary |
static void |
sspgv(int itype,
java.lang.String jobz,
java.lang.String uplo,
int n,
float[] ap,
int _ap_offset,
float[] bp,
int _bp_offset,
float[] w,
int _w_offset,
float[] z,
int _z_offset,
int ldz,
float[] work,
int _work_offset,
intW info)
|
| Methods inherited from class java.lang.Object |
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait |
Sspgv
public Sspgv()
sspgv
public static void sspgv(int itype,
java.lang.String jobz,
java.lang.String uplo,
int n,
float[] ap,
int _ap_offset,
float[] bp,
int _bp_offset,
float[] w,
int _w_offset,
float[] z,
int _z_offset,
int ldz,
float[] work,
int _work_offset,
intW info)