PostScript Plots

Programs are available to produces ASCII PostScript *.ps output of the crystallographic error analysis results. (This assumes you don't have 'Mathematica' or something better.) These are generally per residue bar graphs. These *.ps files are line drawings that may be plotted if you have an appropriate printer/viewer.

Sample data and sample PostScript output may be found in the directory $RIBBONS_HOME/analysis/plot.

The plots may be viewed on an SGI machine by the following:


bf-ps
rsr-ps
rms-ps
geom-ps
dihe-ps
surf-ps
sig-ps

The ribbon-errors script produces ASCII lists of per-residue information. These *.list files are my ``standard'' per residue listing of output. All consist of a required 3-line header, followed by lines of: res# res-name value-res value-mc value-sc.

The default plotting action uses only the res# and values of mainchain (mc) and sidechain (sc). The mc values are shown on top of the X-axis and sc values mirrored below, with the residue number scale below that. Options allow one to change this behavior.

All of these programs have the following usage:

xxx-ps [options] ascii.list > output.ps

Options are:

Secondary Structure Cartoons

A representation of the linear sequence in terms of helix, sheets, and everything else may be generated from a ribbons *.ss file. This will usually be used in conjunction with the per-residue plots above. The options are the same as above, but only the ``-o'' and ``-s'' make any sense:

ss-ps [options] ribbons.ss > output.ps

Ramachandran Plots

Another class of plots are generated from the output of pdb-pro-ss and pdb-chi-ss (which are automatically called by ribbon-errors .) These produce ascii lists which include information on the dihedral angles for each residue.

The ``rama'' plot has circles for each amino acid except glycine, which is marked by a diamond. Allowed regions are shaded according to probability. The lightest regions are allowed only for glycine. The ``chis'' give ramachandran-like plots for each amino acid type. They are generated as follows:

rama-plot < ascii_list.rama > rama.ps
rama-plot "Your title string" < ascii_list.rama > rama.ps
chis-plot < ascii_list.chis > chis.ps

Luzzati Plots

A commonly used error analysis technique is the Luzzati plot. The input is edited from the standard output of X-PLOR's ``print R-factor'' command (see examples described in $RIBBONS_HOME/analysis/plot/Read.Me). Use as follows:

luz-plot [luzOptions] edited_xplor.out > luz.ps


Ribbons User Manual / UAB-CMC / carson@cmc.uab.edu