Table of Contents
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
| <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 |
Typical usage: fitctf jj1023.hed groel.sm
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