XploRe

Overview
XploRe is a computational environment for statistics. The idea of XploRe is not only the application of a fixed set of statistical methods (what is also possible, of course), but also to provide the user with a powerful tool for computational statistics, which comprises a full, high-level programming language and highly interactive graphics.

Design of the Language
It is a procedural language, i.e., the user writes procedures or functions, like in Pascal or C/C++. In contrast to these languages the declaration of variables is not necessary in order to preserve the character of an interpreter. Furthermore, variables can be collected in structures, so that it is possible to hold common information of a data set in a single data object. Of course, all the features of an high-level language like recursion, local variables, loops, and conditional execution are available.

Hard- and Software requirements
Internally the data are represented in C++ classes and all numerical algorithms, the administration of the symbol tables and of the flow control, and finally the most parts of the graphics are implemented in C++, too. XploRe is developed on and for Solaris 2 and Linux 1.2 using X11 and the Motif widget set. Because only standard tools are involved in the development, the installation on other UNIX-like environments should be possible without major difficulties.

Network facilities
The help system is available in HTML and can be used with a common WWW browser. With Java applets the user can also have direct access to XploRe. These applets will generate a full GUI, where even the local generation of graphics is possible. That means, that with a Java including WWW browser a full XploRe session can be opened. Furthermore XploRe is used in the MMM (model management for economic processes) project within the Sonderforschungsbereich 373 at the Humboldt-University as method server beside MatLab, Mathematica etc. Briefly, this project implements a method based extension of WWW and is controlled with browsers like Mosaic, Netscape etc.

The development is a joined project of Swetlana Schmelzer (graphics and graphical user interface), Sigbert Klinke (internal class concept, numerical algorithms), and Thomas Kötter (language design and implementation, Java interface). It has been initiated and is supervised by Prof. Dr. Wolfgang Härdle. Additionally numerous statisticians and econometricians have contributed procedures and libraries written in XploRe.