PXSim Applet Home Page

  John W. Campbell

  Run PXSim in Web page    Launch PXSim from Web page


PXSim is a program, written in Java, for carrying out simulations of Protein Crystallographic diffraction images and analysing the unique data coverage for one or more crystal settings and series of diffraction images. It is intended primarily as a teaching tool to enable the user to investigate, in some depth, the nature of X-ray diffraction patterns and the amount of data which may be collected using various settings or methods. The program may be used for simulating diffraction patterns for the Rotation, Weissenberg and Laue methods of data collection and analysing the extent of data which may be measured using those methods.

The use of Java was chosen so that the program could be made available for use across the internet as well as being in a form suitable for porting to any Java supporting platform.

Much of the functionality is based on code from the CCP4 program suite. The program is based around a Java Development Library (JDL) which includes the JdlView windowing toolkit, objects for handling crystallographic calculations, general purpose objects and objects for handling the keyworded Diffraction Data Module (DDM) set of parameters on which the calculations are based.


PXSim has two inbuilt datasets to enable the user to try out the main features of the program without having to generate a set of input parameters.


For further details on how to use the program see the PXSim User's Guide. Additional details of how to manipulate the JdlView objects used by the program may be found in Part 1 of the JdlView documentation, the JdlView User's Guide

Access to Local Files and Printer

By default, applets are not allowed to access local files. Though all parameters for PXSim can be set up manually, in most cases it will be desirable to enable DDM parameter files to be read and written. A description of how this may be accomplished may be found in the JDL Based Applets and File Access document. Printer access from the applet versions of the program will be likewise restricted.

Running PXSim as an Applet

The program may be run as an applet either with the main program window within the Web page or as a separate window launched from a web page. The required option may be selected via one of the following links:

Run PXSim in Web page

Launch PXSim from Web page

Note: When pages containing applets are left and re-visited, different browsers act in different ways, and not always as they should. The applets have been set up to deal with this as best as possible but, where possible leaving and re-visiting the page while using the applet is best avoided. In any case it should be noted that if a simulation (or unique data coverage) plot is displayed, this will be removed when the page containing the applet is left and that, when the page is re-visited, the program will re-display the main menu. Any DDM parameters input to the program will however retain their values.



August 2005