org.netlib.arpack
Class Sneigh
java.lang.Object
org.netlib.arpack.Sneigh
public class Sneigh
- 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.
*-----------------------------------------------------------------------
\BeginDoc
\Name: sneigh
\Description:
Compute the eigenvalues of the current upper Hessenberg matrix
and the corresponding Ritz estimates given the current residual norm.
\Usage:
call sneigh
( RNORM, N, H, LDH, RITZR, RITZI, BOUNDS, Q, LDQ, WORKL, IERR )
\Arguments
RNORM Real scalar. (INPUT)
Residual norm corresponding to the current upper Hessenberg
matrix H.
N Integer. (INPUT)
Size of the matrix H.
H Real N by N array. (INPUT)
H contains the current upper Hessenberg matrix.
LDH Integer. (INPUT)
Leading dimension of H exactly as declared in the calling
program.
RITZR, Real arrays of length N. (OUTPUT)
RITZI On output, RITZR(1:N) (resp. RITZI(1:N)) contains the real
(respectively imaginary) parts of the eigenvalues of H.
BOUNDS Real array of length N. (OUTPUT)
On output, BOUNDS contains the Ritz estimates associated with
the eigenvalues RITZR and RITZI. This is equal to RNORM
times the last components of the eigenvectors corresponding
to the eigenvalues in RITZR and RITZI.
Q Real N by N array. (WORKSPACE)
Workspace needed to store the eigenvectors of H.
LDQ Integer. (INPUT)
Leading dimension of Q exactly as declared in the calling
program.
WORKL Real work array of length N**2 + 3*N. (WORKSPACE)
Private (replicated) array on each PE or array allocated on
the front end. This is needed to keep the full Schur form
of H and also in the calculation of the eigenvectors of H.
IERR Integer. (OUTPUT)
Error exit flag from slaqrb or strevc.
\EndDoc
-----------------------------------------------------------------------
\BeginLib
\Local variables:
xxxxxx real
\Routines called:
slaqrb ARPACK routine to compute the real Schur form of an
upper Hessenberg matrix and last row of the Schur vectors.
second ARPACK utility routine for timing.
smout ARPACK utility routine that prints matrices
svout ARPACK utility routine that prints vectors.
slacpy LAPACK matrix copy routine.
slapy2 LAPACK routine to compute sqrt(x**2+y**2) carefully.
strevc LAPACK routine to compute the eigenvectors of a matrix
in upper quasi-triangular form
sgemv Level 2 BLAS routine for matrix vector multiplication.
scopy Level 1 BLAS that copies one vector to another .
snrm2 Level 1 BLAS that computes the norm of a vector.
sscal Level 1 BLAS that scales a vector.
\Author
Danny Sorensen Phuong Vu
Richard Lehoucq CRPC / Rice University
Dept. of Computational & Houston, Texas
Applied Mathematics
Rice University
Houston, Texas
\Revision history:
xx/xx/92: Version ' 2.1'
\SCCS Information: @(#)
FILE: neigh.F SID: 2.3 DATE OF SID: 4/20/96 RELEASE: 2
\Remarks
None
\EndLib
-----------------------------------------------------------------------
Field Summary |
static org.netlib.util.floatW |
t0
|
static org.netlib.util.floatW |
t1
|
static float |
t2
|
static float |
t3
|
static float |
t4
|
static float |
t5
|
Method Summary |
static void |
sneigh(float rnorm,
org.netlib.util.intW n,
float[] h,
int _h_offset,
int ldh,
float[] ritzr,
int _ritzr_offset,
float[] ritzi,
int _ritzi_offset,
float[] bounds,
int _bounds_offset,
float[] q,
int _q_offset,
int ldq,
float[] workl,
int _workl_offset,
org.netlib.util.intW ierr)
|
Methods inherited from class java.lang.Object |
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait |
t0
public static org.netlib.util.floatW t0
t1
public static org.netlib.util.floatW t1
t2
public static float t2
t3
public static float t3
t4
public static float t4
t5
public static float t5
Sneigh
public Sneigh()
sneigh
public static void sneigh(float rnorm,
org.netlib.util.intW n,
float[] h,
int _h_offset,
int ldh,
float[] ritzr,
int _ritzr_offset,
float[] ritzi,
int _ritzi_offset,
float[] bounds,
int _bounds_offset,
float[] q,
int _q_offset,
int ldq,
float[] workl,
int _workl_offset,
org.netlib.util.intW ierr)