S.Weber, A.Yamamoto (JWEISS, Weissenberg)

JWEISS 0.95
Java software for analizing pseudo-Weissenberg imaging plate data

introduction

We are presently developing a software package called JWEISS which will be applicable to crystals and quasicrystals and which is to extract reflection intensities from pseudo-Weissenberg imaging plate data. This visually oriented software is written in the JAVA programming language which allows an easy creation of the graphical user interface (GUI). [the C-libraries have been replaced by JAVA routines]
The purpose of this software is to extract the integrated x-ray intensities for the quasicrystal structure analysis. In the pseudo-Weissenberg technique no layer screen is used. Therefore reflections belonging to several layers are recorded on one IP but the rotation angle is limited. By taking a series of images one can therefore record several complete layers including satellite reflections. Especially in the case of quasicrystals this will drastically reduce the time needed for a data collection, since several thousands of reflections can be recorded simultanously.
For displaying and manipulating the data within JWEISS complete reciprocal layers are reconstructed by merging strips from the individual IP files and converting them to GIF images. Furthermore precession photo images are created by a coordinate transformation. These precession photo images serve the determination of some starting parameters, such as initial rotation angle and lattice parameters. Then a Weissenberg simulation is calculated and overlayed on the Weissenberg photo in order to index the peaks. The assigned peaks are then fitted by a profile function in order to obtain the integrated intensities.

IP=imaging plate

main features

Fourier filtering for background correction
creation of Weissenberg layer images (GIF format) by merging strips of the original IPs
creation of Preccesion photographs (GIF format) by coordinate transformation
peak search, lattice parameter determination
calculation of image simulation
assignment of indices to peaks
peak fitting and extraction of integrated intensity
on-screen manipulation of images (histogram, indexing, scaling, moving, ...)
output of PostScript and GIF graphics files
graphical user interface (GUI) with pull-down menus
Precession modul with special features for precession images
IPF modul displays full IP images with found/fitted peak positions

screen captures

Fig. 1	imaging plate example
Fig. 2	jweiss 0.90, window in precession mode (1)
Fig. 3	jweiss 0.90, window in precession mode (2)
Fig. 4	jweiss 0.90, window in histogram mode (1)
Fig. 5	jweiss 0.90, window in histogram mode (2)

Fig. 6	IPF modul (.pk, .int)
Fig. 7	IPF modul (.pk, .int, *.gif)
Fig. 8	jweiss 0.95 (1)
Fig. 9	jweiss 0.95 (2)
Fig. 10	jweiss 0.95 (3)
Fig. 11	jweiss 0.95 (4)

source code file structure

At the moment the file structure is as follows. The external programs are executed by system calls from within the Graphical User Interface (GUI).


JWEISS 0.95  
   |
   |- MAIN PROGRAM ----------- jweiss.java    [ main GUI                                 
   |                      |        |
   |	                  |        |_ jwCanvas.java  [ Weissenberg part                         
   |                      |        
   |	                  |
   |	                  |__ jwPrecession.java      [ Precession GUI                           
   |                      |
   |	                  |__ jwIPF.java             [ IPF modul  GUI                           
   |
   |                               	                           
   | 
   |_ EXTERNAL PROGRAMS ----- weisc0                 [ Simulation of Weissenberg image          
                          |
                          |__ pks                           [ peaksearch  
                          |
                          |__ prf                           [ Intensity extraction and profile fitting

program file structure

below the presently used directory tree is shown.


jweiss                    [ main directory  
   |
   |- project             [ project files containing all needed data      
   |- image               [ Weissenberg *.GIF images                      
   |- data                [ Weissenberg simulation data                   
   |- peaks               [ peak positions & intensities of individual IPs
   |- precession          [ Precession *.GIF images                       
   |- bin                 [ external programs                             
   |- ps                  [ PostScript output                             
   |_ IP                  [ original Imaging Plate data (binaries & GIF)

specifications

source code:	JAVA and C(external programs)
platform:	UNIX, LINUX, WIN95/NT (JDK & C compiler needed)
status:	still under development
authors:	A.Yamamoto & S.Weber NIRIM, Namiki 1-1, Tsukuba, Ibaraki 305, Japan

This work is supported by "Core Research for Evolutional Science and Technology" (CREST) & "Science and Technology Agency" (STA).