org.netlib.arpack
Class Ssgets
java.lang.Object
org.netlib.arpack.Ssgets
public class Ssgets
- 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: ssgets
\Description:
Given the eigenvalues of the symmetric tridiagonal 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: This is called even in the case of user specified shifts in
order to sort the eigenvalues, and error bounds of H for later use.
\Usage:
call ssgets
( ISHIFT, WHICH, KEV, NP, RITZ, BOUNDS, SHIFTS )
\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' -> KEV eigenvalues of largest magnitude are retained.
'SM' -> KEV eigenvalues of smallest magnitude are retained.
'LA' -> KEV eigenvalues of largest value are retained.
'SA' -> KEV eigenvalues of smallest value are retained.
'BE' -> KEV eigenvalues, half from each end of the spectrum.
If KEV is odd, compute one more from the high end.
KEV Integer. (INPUT)
KEV+NP is the size of the matrix H.
NP Integer. (INPUT)
Number of implicit shifts to be computed.
RITZ Real array of length KEV+NP. (INPUT/OUTPUT)
On INPUT, RITZ contains the eigenvalues of H.
On OUTPUT, RITZ are sorted so that the unwanted eigenvalues
are in the first NP locations and the wanted part is in
the last KEV locations. When exact shifts are selected, the
unwanted part corresponds to the shifts to be applied.
BOUNDS Real array of length KEV+NP. (INPUT/OUTPUT)
Error bounds corresponding to the ordering in RITZ.
SHIFTS Real array of length NP. (INPUT/OUTPUT)
On INPUT: contains the user specified shifts if ISHIFT = 0.
On OUTPUT: contains the shifts sorted into decreasing order
of magnitude with respect to the Ritz estimates contained in
BOUNDS. If ISHIFT = 0, SHIFTS is not modified on exit.
\EndDoc
-----------------------------------------------------------------------
\BeginLib
\Local variables:
xxxxxx real
\Routines called:
ssortr ARPACK utility sorting routine.
ivout ARPACK utility routine that prints integers.
second ARPACK utility routine for timing.
svout ARPACK utility routine that prints vectors.
scopy Level 1 BLAS that copies one vector to another.
sswap Level 1 BLAS that swaps the contents of two vectors.
\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/93: Version ' 2.1'
\SCCS Information: @(#)
FILE: sgets.F SID: 2.4 DATE OF SID: 4/19/96 RELEASE: 2
\Remarks
\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 |
ssgets(int ishift,
java.lang.String which,
org.netlib.util.intW kev,
org.netlib.util.intW np,
float[] ritz,
int _ritz_offset,
float[] bounds,
int _bounds_offset,
float[] shifts,
int _shifts_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
Ssgets
public Ssgets()
ssgets
public static void ssgets(int ishift,
java.lang.String which,
org.netlib.util.intW kev,
org.netlib.util.intW np,
float[] ritz,
int _ritz_offset,
float[] bounds,
int _bounds_offset,
float[] shifts,
int _shifts_offset)