org.netlib.arpack
Class Sngets
java.lang.Object
org.netlib.arpack.Sngets
public class Sngets
- 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: sngets
\Description:
Given the eigenvalues of the upper Hessenberg matrix H,
computes the NP shifts AMU that are zeros of the polynomial of
degree NP which filters out components of the unwanted eigenvectors
corresponding to the AMU's based on some given criteria.
NOTE: call this even in the case of user specified shifts in order
to sort the eigenvalues, and error bounds of H for later use.
\Usage:
call sngets
( ISHIFT, WHICH, KEV, NP, RITZR, RITZI, BOUNDS, SHIFTR, SHIFTI )
\Arguments
ISHIFT Integer. (INPUT)
Method for selecting the implicit shifts at each iteration.
ISHIFT = 0: user specified shifts
ISHIFT = 1: exact shift with respect to the matrix H.
WHICH Character*2. (INPUT)
Shift selection criteria.
'LM' -> want the KEV eigenvalues of largest magnitude.
'SM' -> want the KEV eigenvalues of smallest magnitude.
'LR' -> want the KEV eigenvalues of largest real part.
'SR' -> want the KEV eigenvalues of smallest real part.
'LI' -> want the KEV eigenvalues of largest imaginary part.
'SI' -> want the KEV eigenvalues of smallest imaginary part.
KEV Integer. (INPUT/OUTPUT)
INPUT: KEV+NP is the size of the matrix H.
OUTPUT: Possibly increases KEV by one to keep complex conjugate
pairs together.
NP Integer. (INPUT/OUTPUT)
Number of implicit shifts to be computed.
OUTPUT: Possibly decreases NP by one to keep complex conjugate
pairs together.
RITZR, Real array of length KEV+NP. (INPUT/OUTPUT)
RITZI On INPUT, RITZR and RITZI contain the real and imaginary
parts of the eigenvalues of H.
On OUTPUT, RITZR and RITZI are sorted so that the unwanted
eigenvalues are in the first NP locations and the wanted
portion is in the last KEV locations. When exact shifts are
selected, the unwanted part corresponds to the shifts to
be applied. Also, if ISHIFT .eq. 1, the unwanted eigenvalues
are further sorted so that the ones with largest Ritz values
are first.
BOUNDS Real array of length KEV+NP. (INPUT/OUTPUT)
Error bounds corresponding to the ordering in RITZ.
SHIFTR, SHIFTI *** USE deprecated as of version 2.1. ***
\EndDoc
-----------------------------------------------------------------------
\BeginLib
\Local variables:
xxxxxx real
\Routines called:
ssortc ARPACK sorting routine.
scopy Level 1 BLAS that copies one vector to another .
\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: ngets.F SID: 2.3 DATE OF SID: 4/20/96 RELEASE: 2
\Remarks
1. xxxx
\EndLib
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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 |
sngets(int ishift,
java.lang.String which,
org.netlib.util.intW kev,
org.netlib.util.intW np,
float[] ritzr,
int _ritzr_offset,
float[] ritzi,
int _ritzi_offset,
float[] bounds,
int _bounds_offset,
float[] shiftr,
int _shiftr_offset,
float[] shifti,
int _shifti_offset)
|
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
Sngets
public Sngets()
sngets
public static void sngets(int ishift,
java.lang.String which,
org.netlib.util.intW kev,
org.netlib.util.intW np,
float[] ritzr,
int _ritzr_offset,
float[] ritzi,
int _ritzi_offset,
float[] bounds,
int _bounds_offset,
float[] shiftr,
int _shiftr_offset,
float[] shifti,
int _shifti_offset)