R is a well-documented statistics package. http://www.r-project.org/
BR -----Original Message----- From: CCP4 bulletin board [mailto:CCP4BB@JISCMAIL.AC.UK] On Behalf Of Keitaro Yamashita Sent: Sunday, February 06, 2011 2:10 AM To: CCP4BB@JISCMAIL.AC.UK Subject: Re: [ccp4bb] adding gaussian noise to an mtz data column Dear James, I'm very interested in your crystallographic R package. Is it available to the public? Thanks in advance, Keitaro 2011/2/4 James Foadi <james_fo...@yahoo.co.uk>: > 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. > > > > >
