[cctbxbb] Electron density hitogram from MTZ file

[castro at biochem.mpg.de]

Hi everybody,

I am new in crystallogrphy and in the use of cctbx.
I am interested in building a electron density histogram from a mtz file.
Could somebody give a hint on how to accomplish this task using cctbx  
libraries (I am scripting in python)?

Let's say that I already have the columns of interest as "miller arrays".
Then (I think), a grid (on the real space) needs to be created based  
on unit cell parameters, to finally make the fft.

I think that most of my doubts are about the grid.
How small the grid should be with respect to the low-resolution limit?
Does the space group information needed or it is enough with the the  
cell parameters?

Is there all ready a routine doing this?

Thanks a lot for your help.

Marcelino