org.netlib.lapack
Class Sstevd
java.lang.Object
org.netlib.lapack.Sstevd
public class Sstevd
- 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
* =======
*
* SSTEVD computes all eigenvalues and, optionally, eigenvectors of a
* real symmetric tridiagonal matrix. If eigenvectors are desired, it
* uses a divide and conquer algorithm.
*
* The divide and conquer algorithm makes very mild assumptions about
* floating point arithmetic. It will work on machines with a guard
* digit in add/subtract, or on those binary machines without guard
* digits which subtract like the Cray X-MP, Cray Y-MP, Cray C-90, or
* Cray-2. It could conceivably fail on hexadecimal or decimal machines
* without guard digits, but we know of none.
*
* Arguments
* =========
*
* JOBZ (input) CHARACTER*1
* = 'N': Compute eigenvalues only;
* = 'V': Compute eigenvalues and eigenvectors.
*
* N (input) INTEGER
* The order of the matrix. N >= 0.
*
* D (input/output) REAL array, dimension (N)
* On entry, the n diagonal elements of the tridiagonal matrix
* A.
* On exit, if INFO = 0, the eigenvalues in ascending order.
*
* E (input/output) REAL array, dimension (N)
* On entry, the (n-1) subdiagonal elements of the tridiagonal
* matrix A, stored in elements 1 to N-1 of E; E(N) need not
* be set, but is used by the routine.
* On exit, the contents of E are destroyed.
*
* Z (output) REAL array, dimension (LDZ, N)
* If JOBZ = 'V', then if INFO = 0, Z contains the orthonormal
* eigenvectors of the matrix A, with the i-th column of Z
* holding the eigenvector associated with D(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/output) REAL array,
* dimension (LWORK)
* On exit, if INFO = 0, WORK(1) returns the optimal LWORK.
*
* LWORK (input) INTEGER
* The dimension of the array WORK.
* If JOBZ = 'N' or N <= 1 then LWORK must be at least 1.
* If JOBZ = 'V' and N > 1 then LWORK must be at least
* ( 1 + 4*N + N**2 ).
*
* 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.
*
* IWORK (workspace/output) INTEGER array, dimension (LIWORK)
* On exit, if INFO = 0, IWORK(1) returns the optimal LIWORK.
*
* LIWORK (input) INTEGER
* The dimension of the array IWORK.
* If JOBZ = 'N' or N <= 1 then LIWORK must be at least 1.
* If JOBZ = 'V' and N > 1 then LIWORK must be at least 3+5*N.
*
* If LIWORK = -1, then a workspace query is assumed; the
* routine only calculates the optimal size of the IWORK array,
* returns this value as the first entry of the IWORK array, and
* no error message related to LIWORK is issued by XERBLA.
*
* INFO (output) INTEGER
* = 0: successful exit
* < 0: if INFO = -i, the i-th argument had an illegal value
* > 0: if INFO = i, the algorithm failed to converge; i
* off-diagonal elements of E did not converge to zero.
*
* =====================================================================
*
* .. Parameters ..
|
Method Summary |
static void |
sstevd(java.lang.String jobz,
int n,
float[] d,
int _d_offset,
float[] e,
int _e_offset,
float[] z,
int _z_offset,
int ldz,
float[] work,
int _work_offset,
int lwork,
int[] iwork,
int _iwork_offset,
int liwork,
intW info)
|
| Methods inherited from class java.lang.Object |
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait |
Sstevd
public Sstevd()
sstevd
public static void sstevd(java.lang.String jobz,
int n,
float[] d,
int _d_offset,
float[] e,
int _e_offset,
float[] z,
int _z_offset,
int ldz,
float[] work,
int _work_offset,
int lwork,
int[] iwork,
int _iwork_offset,
int liwork,
intW info)