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: [log in to unmask]
alternative email: [log in to unmask]
----- Original Message ----
From: Vellieux Frederic <[log in to unmask]>
To: [log in to unmask]
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.
