If you fancy using R (and its endless ways of generating random deviates), then you could use part of the crystallographic package we are developing here (cRy).
Then you would carry out the following in R: > source("cRy/all_load.R") > mtz <- >readMTZ("test.mtz") > > # Load data from mtz file > newF <- mtz$reflections$Fnew+rnorm(mean=0,sd=1,n=length(mtz$reflections$H)) > # >Add gaussian deviates with mean 0 and standard dev 1 > mtz$reflections$Fnew <- >newF > ># Replace new column >writeMTZ(mtz,"new_test.mtz") > > # Write modified file with a different name If you are interested I can provide you with my R code for doing this. J Dr James Foadi PhD Membrane Protein Laboratory Diamond Light Source Ltd. Diamond House Harwell Science and Innovation Campus Didcot Oxfordshire OX11 0DE United Kingdom office email: james.fo...@diamond.ac.uk alternative email: j.fo...@imperial.ac.uk ----- Original Message ---- From: Vellieux Frederic <frederic.velli...@ibs.fr> To: CCP4BB@JISCMAIL.AC.UK Sent: Fri, 4 February, 2011 12:40:35 Subject: [ccp4bb] adding gaussian noise to an mtz data column Before re-inventing the wheel... Is there anywhere some software (freely available software, I mean) that can add some Gaussian noise to data. The data is currently stored in a data column in an mtz (not phase data, but "amplitudes", "sigma values"...) but can be exported to another format if required. Before writing a computer program to do this, does anyone know if this can be done without writing any code. If it can then obviously I won't write new code. Thanks, Fred.