Introduction

chifig is a Ruby program that reads an input specification of a figure, consisting of one or more 2D (x,y) plots, and creates a publication quality Postscript representation of the figure. The input specification can be either JSON, created by any other program, or a domain-specific minilanguage (DSL) that is much more concise than JSON.

chifig can read data from text files or generate data from mathematical expressions. Every feature of a figure can be customized, but chifig provides sensible default values for most features, so figures can be generated quickly, without adjusting too many settings.

Requirements

In addition to Ruby, chifig uses latex and dvips to generate figures. It relies on the following latex packages:

• pstricks
• pst-plot
• standalone

In Ubuntu, these requirements are fulfilled by installing the following packages:

• texlive
• texlive-pstricks
• texlive-latex-extra

Most TeX distributions (such as TeX Live) provide latex, these packages, and dvips.

The installation process requires Rake (see below).

Example

# 
# A simple DSL example: plot the sinc function
# 
plot {
   title 'Sinc function'
   key hide
   xaxis {title 'x'}
   yaxis {
      title 'sin(x)/x'
      min -0.5
      max 1.5
   }
   curve {
      generate 'sin(x)/x', -10, 10, 0.2
      line solid, blue
      symbol none
   }
}

See the equivalent JSON input of this example here.

For more examples, see the gallery.

Installation

All installation options are defined in the file install_config.rb in the top source directory. To see the current configuration, use this command:

rake show_config

Edit install_config.rb to customize any installation paths, then type

(sudo) rake install

This command may require elevated privileges (sudo) to install to system directories.

Usage

After installing all components (see above), invoke chifig from the command line with the following command:

chifig  infile  psfile

where infile may be a JSON file or a DSL file.

chide

chide is an interactive development environment for figures generated with the chifig DSL. chide launches your favorite editor and Ghostscript. As you edit and save a DSL input file in the editor, the Ghostscript window will display the resulting Postscript. Invoke chide from the command line with this command:

chide [infile] [psfile] [width] [height]

The optional arguments include the input file (default: figure.in), the output Postscript file (default: figure.ps), the Ghostscript window width and height (default: 245).