fitctf
This program estimates CTF parameters in batch. The results should be checked in CTFIT
Usage
fitctf <input file> [sf=<SF File>] [apix=<a/pix>] [V=<voltage>] [Cs=<spher aber>] [over=<oversampling>] [acmax=<max AC>] [acfix=<max AC>] [Bhint=<B factor] [Bfix=<B factor>] [Bexp] [debug]
Parameters
- Typical usage: fitctf jj1023.hed groel.sm
<input file>
File containing boxed particles to be evaluated
[sf=<SF File>]
File containing estimated 1D structure factor for this specimen
[apix=<a/pix>]
Angstroms/pixel in the image
[V=<voltage>]
Voltage in KV
[Cs=<spher aber>]
Spherical aberation in mm
[over=<oversampling>]
eg - 2 -> 2x oversampling
[acmax=<max AC>]
eg - .1 is max 10% ac, default is .14
[acfix=<max AC>]
fixed amplitude contrast
[Bhint=<B factor]
A strong hint for the B-factor, strictly optional
[Bfix=<B factor>]
Force the B factor to a specific value
[Bexp]
Use an exponential 'B-factor' rather than a Gaussian
[debug]
Verbose debugging output
Description
This program will attempt to determine the CTF parameters of a a set of particles. It will write the result into a .tnf file, which can then be read into ctfit. The results of this program should always be manually verified in ctfit. This program is just designed to save the user a little manual effort.
If you have a fairly small model (size in pixels < 128) or are very far from focus, you might consider using the oversampling option with a value of 2 or 3.
Please note that this program uses an exceptionally inefficient algorithm. However, there is a lot of embedded 'magic' in this routine. It is designed to be functional, not fast.
EMAN Manual page, generated Mon Jan 8 17:35:59 2007