Getting the PISA output files into CLUSTAN

It is possible to get PISA format data into CLUSTAN and do analyses based on the `natural' clustering of the RESULTS. The analyses are highly dependent on the similarity measure (the distance in the parameter space) and consequently the clustering which is found is more often than not due to the measure rather than the physical attributes of the objects. In runs of CLUSTAN on the test NDF `FRAME' in the PISA directory seem to select strongly by angle and the sign of the cross moment (SXY), and very weakly in others (ellipticity for one) which one might expect to bear more relevance to the real `clustering'. This problem probably requires careful selection of the variables to use and may well require the production of new hybrid variables (things like intensity/peak) as performed by PISAPEAK.

A description of the entry of PISA data into CLUSTAN is given below and an analysis using this may be attempted, however, NO significance should be ascribed to the results. If you really want to use this method there is no substitute to a proper understanding.

A file called clustan.dat is found in $PISA_DIR, take a copy of it. It shows how to get data into CLUSTAN, to run it in `batch' mode simply change the file names to those of your PISAFIND data files and type.

   # clustan < clustan.dat