clip (the command line illustration processor) is an open-source command line program and software library for creating charts and other data-driven illustrations.

In essence, clip consists of a library of drawing commands. This command library includes high-level building blocks for creating common chart types as well as lower-level drawing primitives such as markers, arrows and lines.

When called from the command line, clip reads input data in text and CSV format and produces the output chart as a SVG or PNG file. Additionaly, clip is available as the libclip software library which can be embedded into any application that supports a C FFI.

Being a highly visual tool, clip is best explained by example. So here is how to draw a simple line chart using clip:

$ clip --export example_chart.svg example_chart.clp

Output File (example_chart.svg):

Input File (example_chart.clp):

(figure/plot
    limit-x (1404278100 1404299700)
    limit-y (6000000 10000000)
    axes (
        position (bottom left)
        label-format-y (scientific)
        label-format-x (datetime "%H:%M:%S")
        label-placement-x (linear-align 1800))
    lines (
        data-x (csv "test/testdata/measurement.csv" time)
        data-y (csv "test/testdata/measurement.csv" value1)
        color #06c)
    legend (
        position (top right)
        item (label "Random Data" color #06c)))

Note that this example is only intended to give you an idea of what the syntax looks like and to get you started quickly; for an in-depth description of all parameters, please refer to the documentation.

More examples can be found on the examples page.

If you have any questions please don't hesitate to reach out via GitHub issues.

You can find the full documentation at https://clip-lang.org/

A list of examples can be found on the Examples page.

To build clip, you need an up-to-date C++ compiler, cmake, fmtlib, libharfbuzz, libfreetype and cairo. Run:

$ cmake .
$ make

To install the clip binary into your system, run make install:

$ make install

To run the test suite, run make test:

$ make test

For detailed installation instructions, have a look at the Installation page.

• Text rendering is based on the libre freetype and harfbuzz stack.

• The structure of the plot elements is based on ideas from The Grammar of Graphics and the ggplot2 library.

• A number of concepts in clip are modelled after the CSS specification

clip is written in C++17 and needs a reasonably modern C++ compiler and standard library. In most cases where the code doesn't build it's due to some problem with the local build environment. We always appreciate bug reports so that we can improve our build system on GitHub Issues.

The test suite requires that you have the original Microsoft Arial TTF files installed on your machine. To verify that this is the case, run fc-match 'Arial,Helvetica,Helvetica Neue:style=Regular,Roman' and check that it returns the correct 'arial.ttf' file.

The project was started in 2011 and was initially called "FnordMetric". The first version from 8 years ago also included facilities for storing and transforming data in addition to the charting code. Over time, the data processing parts were removed, leaving only the plotting code. However, as a consequence, most of the search queries for the project name would return outdated information, resulting in a generally confusing and stale-feeling situation. The best solution seemed to be to rename the project and so it was renamed to "clip".

clip -- The command line illustration processor
https://clip-lang.org

Copyright (c) 2018, Paul Asmuth, Laura Schlimmer
All rights reserved.

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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