# pandoc-pyplot
[](https://ci.appveyor.com/project/LaurentRDC/pandoc-pyplot)
_A Pandoc filter for generating figures with Matplotlib from code directly in documents_
Inspired by [sphinx](https://sphinxdoc.org)'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:
```markdown
```{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:
```bash
pandoc --filter pandoc-pyplot input.md --output output.html
```
or
```bash
pandoc --filter pandoc-pyplot input.md 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.
### Alternate text
You can also specify some alternate text for your image. This is done using the optional `plot_alt` parameter:
```markdown
```{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')
```
```
## Requirements
This filter only works with the Matplotlib plotting library. Therefore, you need [Matplotlib](matplotlib.org) and a Python interpreter. The python interpreter is expected to be discoverable using the name `"python"` (as opposed to `"python3"`, for example)
## Running the filter
The filter program must be in your `PATH`. In case it is, you can use the filter with Pandoc as follows:
```bash
pandoc --filter pandoc-pyplot input.md output.html
```
Another example with PDF output:
```bash
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:
```bash
pandoc-pyplot --help
```
## Usage as a Haskell library
To include the functionality of `pandoc-pyplot` in a Haskell package, you can use the `makePlot` function:
```haskell
-- From pandoc-types
import Text.Pandoc.Walk (walkM)
import Text.Pandoc.Definition (Pandoc)
-- From pandoc-pyplot
import Text.Pandoc.Filter.Pyplot (makePlot)
transformDocument :: Pandoc -> IO Pandoc
transformDocument = walkM makePlot
```
## Usage with Hakyll
This filter was originally designed to be used with [Hakyll](https://jaspervdj.be/hakyll/). In case you want to use the filter with your own Hakyll setup, you must create a transform function first:
```haskell
-- From pandoc-types
import Text.Pandoc (Pandoc)
import Text.Pandoc.Walk (walkM)
-- from pandoc-pyplot
import Text.Pandoc.Filter.Pyplot (makePlot)
import Hakyll
plotTransform :: Pandoc -> IO Pandoc
plotTransform = walkM . makePlot
-- 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)
```
## Aknowledgements
This package is inspired from [`pandoc-include-code`](https://github.com/owickstrom/pandoc-include-code).