pandoc-pyplot
A Pandoc filter for generating figures with Matplotlib from code directly in documents
Inspired by sphinx’s plot_directive
, pandoc-pyplot
helps turn Python code present in your documents to embedded Matplotlib figures.
Usage
The filter recognizes code blocks with the plot_target
attribute present. It will run the script in the associated code block in a Python interpreter and capture the generated Matplotlib figure. This captured figure will be saved in the located specific by plot_target
.
Basic example
Here is a basic example using the scripting matplotlib.pyplot
API:
```{plot_target=my_figure.jpg}
import matplotlib.pyplot as plt
plt.figure()
plt.plot([0,1,2,3,4], [1,2,3,4,5])
plt.title('This is an example figure')
```
pandoc-pyplot
will determine whether the plot_target
is a relative or absolute path. In case of a relative path (like above), all paths will be considered relative to the current working directory.
We can control the format of the output file by changing the plot_target
file extension. All formats supported by Matplotlib on your machine are available.
Putting the above in input.md
, we can then generate the plot and embed it:
pandoc --filter pandoc-pyplot input.md --output output.html
or
pandoc --filter pandoc-pyplot input.md --output output.pdf
or any other output format you want. There are more examples in the source repository, in the \examples
directory.
Link to source code
In case of an output format that supports links (e.g. HTML), the embedded image generated by pandoc-pyplot
will be a link to the source code which was used to generate the file. Therefore, other people can see what Python code was used to create your figures.
Captions
You can also specify a caption for your image. This is done using the optional plot_alt
parameter:
```{plot_target=my_figure.jpg, plot_alt="This is a simple figure"}
import matplotlib.pyplot as plt
plt.figure()
plt.plot([0,1,2,3,4], [1,2,3,4,5])
plt.title('This is an example figure')
```
Installation
Binaries
Windows binaries are available on GitHub. Place the executable in a location that is in your PATH to be able to call it.
From Hackage/Stackage
pandoc-pyplot
is available on Hackage. Using the cabal-install
tool:
cabal update
cabal install pandoc-pyplot
Similarly, pandoc-pyplot
is available on Stackage:
stack update
stack install pandoc-pyplot
From source
Building from source can be done using stack
or cabal
:
git clone github.com/LaurentRDC/pandoc-pyplot.git
cd pandoc-pylot
stack install # Alternatively, `cabal install`
Running the filter
Requirements
This filter only works with the Matplotlib plotting library. Therefore, you a Python interpreter and at least Matplotlib installed. The python interpreter is expected to be discoverable using the name "python"
(as opposed to "python3"
, for example)
The filter program must be in your PATH
. In case it is, you can use the filter with Pandoc as follows:
pandoc --filter pandoc-pyplot input.md output.html
Another example with PDF output:
pandoc --filter pandoc-pyplot input.md output.pdf
Python exceptions will be printed to screen in case of a problem.
pandoc-pyplot
has a very limited command-line interface. Take a look at the help available using the -h
or --help
argument:
pandoc-pyplot --help
Usage as a Haskell library
To include the functionality of pandoc-pyplot
in a Haskell package, you can use the makePlot :: Block -> IO Block
function (for single blocks) or plotTransform :: Pandoc -> IO Pandoc
function (for entire documents).
Usage with Hakyll
This filter was originally designed to be used with Hakyll. In case you want to use the filter with your own Hakyll setup, you can use a transform function that works on entire documents:
import Text.Pandoc.Filter.Pyplot (plotTransform)
import Hakyll
-- Unsafe compiler is required because of the interaction
-- in IO (i.e. running an external Python script).
makePlotPandocCompiler :: Compiler (Item String)
makePlotPandocCompiler =
pandocCompilerWithTransformM
defaultHakyllReaderOptions
defaultHakyllWriterOptions
(unsafeCompiler . plotTransform)
Warning
Do not run this filter on unknown documents. There is nothing in pandoc-pyplot
that can stop a Python script from performing evil actions. This is the reason this package is deemed unsafe in the parlance of Safe Haskell.
Aknowledgements
This package is inspired from pandoc-include-code
.