Re: GSL and Java

[Luc Maisonobe <Luc dot Maisonobe at c-s dot fr>]

Eugenio Rodriguez wrote:

> I would like to know if there is anything
> like the GSL for Java, or at least something concering numerical
> methods for differential equations (Runge-Kutta...).

You can have a look at mantissa and rkcheck
(http://www.spaceroots.org/archive.htm#MantissaSoftware and
http://www.spaceroots.org/archive.htm#RKCheckSoftware).

Mantissa is a small library where I gather some algorithms I need for
space applications, it includes several differential integration scheme,
including various Runge-Kutta and Runge-Kutta-Fehlberg algorithms as
well as the Gragg-Bulirsch-Stoer method.

Rkcheck is a tool to check the order of a Runge-Kutta-Fehlberg method.
It build the order conditions analytically and check the Butcher arrays
specified by the user in a simple XML file. There are several examples
files in the spaceroots site. There is also another application embedded
inside rkcheck that can write the order conditions as a TeX file.

In order to launch the checker you should do :
  java -jar rkcheck.jar SomeButcherArrayFile.xml 

And if you want to build the order equations up to order 8 you should do
:
  java -classpath rkcheck.jar \
       org.spaceroots.rkcheck.ComputeOrderConditions -t 8 > x.tex

Do not hesitate to ask me directly if you have any question or need
enhancements in the library.

                                                    Luc