Customising plots

Command-line options

Several of Euphonic’s Command-line Tools produce 2D plots. A few command-line arguments are provided to tweak the plot size, font settings and colour maps, e.g.:

euphonic-dos --font Monaco --fontsize 18 --figsize 10 10 --figsize-unit cm quartz.castep_bin

will produce a plot with larger (hopefully monospace) text on a small square canvas. This may be especially useful with the --save-to option to create consistent plots for presentation slides and academic papers.

The --font option will be passed to the Matplotlib library as the preferred “sans-serif” option, and the font family will be set to sans-serif. Unfortunately it can be tricky to identify exactly which font names are accepted by Matplotlib. We cannot advise on this for all platforms, so if you have a preferred font it may be worth searching for help on using this font with Matplotlib.

Using Matplotlib styles

These and other appearance customisations can be defined as a Matplotlib style sheet. A number of popular styles are predefined in Matplotlib and may be accessed by name, e.g.:

euphonic-dos --pdos --style seaborn quartz.castep_bin

will yield a plot on a grey background with white gridlines.

PDOS plot with thin dark blue, red and green lines against a pale grey background divided by white gridlines. There are no outlines around the legend (top-right) or the axes; number values are in a black sans-serif and float near the plot.

--style=dark_background might be preferred for some slide presentations.

Using custom stylesheets

For a custom scheme, you can develop your own style file. For example, with the following file saved as “custom.mplstyle”

axes.facecolor: floralwhite
font.family: monospace
text.color: grey
lines.linewidth : 3
xtick.labelsize : smaller
legend.fancybox: True
legend.shadow: True
figure.figsize : 3, 3
figure.facecolor : palegoldenrod

then the command:

euphonic-dos quartz.castep_bin --pdos --style custom.mplstyle

generates a small figure with some “opinionated” styling.

A square PDOS plot with very thick blue, orange and green data lines, a pale yellow background and pinkish off-white canvas. The canvas is surrounded by black lines with numbered ticks. On the canvas are vertical grey gridlines and a legend with drop shadow, round corners and grey text. The label text is in a monospace font.

It is possible to “compose” multiple styles in ascending priority order, e.g.:

euphonic-dos quartz.castep_bin --pdos --style seaborn custom.mplstyle

In the resulting figure, the customised text and canvas options have taken priority, but we still get the Seaborn colour sequence for plot lines. The plot outline, ticks and legend box were removed. (And with them, the legend customisation!)

A very similar plot to the above, except that the legend box is gone (along with its shadow), and the line colours are now a tasteful blue, green and (desaturated) red combination. The grid lines are white against a pale orange background.

For a large project, this can be very useful to establish a general “house style” with variations for certain plot types. However, as seen above, combining styles can sometimes have unexpected consequences. In order to prevent conflict between Euphonic’s own stylesheet and other style options, the --no-base-style argument can be used to remove the Euphonic defaults. For example, with the seaborn style this will restore the horizontal grid lines that are expected to replace the missing black ticks.