Calculate average I/sigma from .sca file

From CCP4 wiki

This python script will analyze a .sca-file and print out the key statistics missing from the standard SCALEPACK log-file, namely [math]\lt I/sigma\gt [/math] per resolution shell. Syntax is quite simple

 ./ioversigma.py <.sca-file name> <number of shells>

The number of shells is an optional parameter and defaults to 10 if omitted.

Get ioversigma.py here

This works on merged intensities, i.e. the standard scalepack output. An alternative below uses the unmerged output from scalepack.


An alternative is to use SCALA (you will also need to assign the cell and symmetry) after pointless :

pointless -c scain ... 
scala hklin from_pointless.mtz hklout merged.mtz << eof
run 1 all
scales constant
sdcorrection noadjust norefine both 1 0 0
cycles 0
eof

This will just remerge the measurements and give you the usual merging analysis from Scala. Same trick also works with data from XDS/XSCALE; in that case use

pointless xdsin ...


Back to Useful scripts (aka smart piece of code)