dtdisplay on-line help
Getting Started
When you collect and process single crystal diffraction images from a position-sensitive
detector, it is very useful to visualize or see the images. You want to check that the
crystal diffracts and that the Bragg peaks can be integrated. The suitability of a crystal for
further data collection and analysis depends on a number of factors and compromises.
Among these factors are:
- crystal unit cell
- spot shape (no split peaks or satellites)
- diffraction limit
- spot separation
- exposure time
- rotation angle increment
- detector position
For example, if the unit cell lengths are large, then the diffraction spots will be spaced
close together and the detector will have to be moved further from the crystal. Often only
by viewing images can you judge whether or not you should collect diffraction data from a
crystal. The dtdisplay program displays images and allows you to decide whether to
proceed.
dtdisplay uses a color X Window display and the OSF/Motif widget set and style. Both
X and OSF/Motif are widely used on workstations, so you may already by familiar with
them and consequently already know how to run and use dtdisplay. If you are not
familiar, do not worry as dtdisplay is very easy to use and comes with many help features.
Before you start dtdisplay be sure your DISPLAY environment variable is set to your
current display and the Dtdisplay application defaults file is accessible to your X server.
The latter file can be placed in the system-wide application defaults directory (e.g.
usr/lib/X11/app-defaults) or in your home directory. Please consult the installation
guide in section 5 and your system manager.
Running dtdisplay
After dtdisplay has been installed and placed in your PATH, just enter dtdisplay along
wiith an optional image filename to run it. Since dtdisplay is an X Window program the
standard X command line options are also supported. Messages are written to stdout and
stderr as required. The syntax for running dtdisplay is simply:
dtdisplay [image_file]
Remember, the image filename after the dtdisplay command is optional.