Xdsstat

XDSSTAT is a home-brewn program that prints various statistics (that are not available from XDS itself) in the form of tables and images.

Usage

The program reads from a file written by CORRECT or XSCALE (default: XDS_ASCII.HKL). Before using the program, you have to set up a CCP4 environment, because it uses the CCP4 routines and files.

As the output is long, it should be called as

xdsstat > XDSSTAT.LP

This will probably soon be changed to the XDS style.

The program may be called with two parameters which define the resolution range of data to be read:

xdsstat 20 3 > XDSSTAT.LP

Features

Tables

• statistics: for each frame: # reflections, # misfits, I, sigma(I), I/sigma(I), fraction of reflections observed, correlation with standard profiles, R_meas and # reflections used for R_meas, # unique reflections which only occur on this frame and would thus be lost if this frame were deleted from the dataset. These lines end with " L" which may be used for "grepping" them from XDSSTAT.LP:

grep ' L$' XDSSTAT.LP > L

• R-factors as a function of frame number difference (R[math]\displaystyle{ _d }[/math] , see Diederichs K. (2006) Some aspects of quantitative analysis and correction of radiation damage. Acta Cryst D62, 96-101). These lines end with " DIFFERENCE" which may be used for "grepping" them from XDSSTAT.LP:

grep DIFFERENCE XDSSTAT.LP > D

Images

The following quantities mapped onto the detector surface:

• misfits.pck: outliers identified in CORRECT. Useful e.g. to identify ice rings.
• rf.pck: R-factor (very interesting)
• anom.pck: anomalous signal (very interesting)
• scales.pck: scale factors between symmetry-related reflections (very interesting)
• nobs.pck: observed reflections (not very interesting)
• rlps.pck: reciprocal lorentz factor (not very interesting)

These images are in the .pck format and may be visualized by VIEW.

N.B.: Images are currently only produced for reflection files coming from XDS, not for those from XSCALE. The reason is that the latter lack a line like

!NX=  2048  NY=  2048    QX=  0.079090  QY=  0.079090

which is used to tell the program how big the detector is. If you want image output for XSCALE reflection files, just copy this line into it.

Availability

A Linux binary is at [1].

I (Kay dot Diederichs at uni-konstanz dot de) appreciate feedback.

The source code is in Fortran90 and requires a Fortran90-compiled CCP4 library, so few people are currently in a position to compile and link the program. I might opensource it someday, but preferably as part of the XDS distribution.