Re: [ccp4bb] Back-Fourier transforming an EM map with SFALL

2008-03-20 Thread Bruno Klaholz
Dear Larry, you may have to coarsen and cut your map into 120,120,120 (full sampling may not be needed anyway for MR) or try cutting into 240,240,240 (though I haven't tried such big values yet). I noticed that you have already converted the axes to XYZ (I guess with the uvw option in

Re: [ccp4bb] Back-Fourier transforming an EM map with SFALL

2008-03-20 Thread Alejandro Buschiazzo
Hi, I recall some 'constraints' on the grid numbers; if I remember well, at least y and z have to be even in P1 (and the same grid had to be used in fft to create the map in the first place...) Less sure than this first limit (so please correct me if I'm wrong!)...two more restriction limits

[ccp4bb] Back-Fourier transforming an EM map with SFALL

2008-03-19 Thread Lawrence Shapiro
Hello All, I'm trying to back-FT an EM map to produce Fs and phases to use in molecular replacement, but am having a problem with running SFALL. Here's the issue: When running the back-transform in SFALL (generating structure factors from a map), I get the following error: Incorrect sampling