Text.Pandoc.Filter.Pyplot

This module defines a Pandoc filter makePlot that can be used to walk over a Pandoc document and generate figures from Python code blocks.

The syntax for code blocks is simple, Code blocks with the .pyplot attribute will trigger the filter. The code block will be reworked into a Python script and the output figure will be captured, along with a high-resolution version of the figure and the source code used to generate the figure.

To trigger pandoc-pyplot, the following is required:

• .pyplot: Trigger pandoc-pyplot but let it decide on a filename

Here are the possible attributes what pandoc-pyplot understands:

• directory=... : Directory where to save the figure.
• format=...: Format of the generated figure. This can be an extension or an acronym, e.g. format=png.
• caption="...": Specify a plot caption (or alternate text). Captions support Markdown formatting and LaTeX math ($...$).
• dpi=...: Specify a value for figure resolution, or dots-per-inch. Default is 80DPI.
• include=...: Path to a Python script to include before the code block. Ideal to avoid repetition over many figures.

Here are some example blocks in Markdown:

This is a paragraph

```{.pyplot caption="This is a caption."}
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')
```

This is another paragraph

```{.pyplot dpi=150 format=SVG}
# This example was taken from the Matplotlib gallery
# https://matplotlib.org/examples/pylab_examples/bar_stacked.html

import numpy as np
import matplotlib.pyplot as plt

N = 5
menMeans = (20, 35, 30, 35, 27)
womenMeans = (25, 32, 34, 20, 25)
menStd = (2, 3, 4, 1, 2)
womenStd = (3, 5, 2, 3, 3)
ind = np.arange(N)    # the x locations for the groups
width = 0.35       # the width of the bars: can also be len(x) sequence

p1 = plt.bar(ind, menMeans, width, color='#d62728', yerr=menStd)
p2 = plt.bar(ind, womenMeans, width,
             bottom=menMeans, yerr=womenStd)

plt.ylabel(Scores)
plt.title('Scores by group and gender')
plt.xticks(ind, (G1, G2, G3, G4, G5))
plt.yticks(np.arange(0, 81, 10))
plt.legend((p1[0], p2[0]), (Men, Women))
```

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)

Custom configurations are possible via the Configuration type and the filter functions plotTransformWithConfig and makePlotWithConfig.

Operating on single Pandoc blocks

makePlot :: Block -> IO Block

Highest-level function that can be walked over a Pandoc tree. All code blocks that have the '.pyplot' parameter will be considered figures.

makePlotWithConfig :: Configuration -> Block -> IO Block

like makePlot with with a custom default values.

Since: 2.1.0.0

Operating on whole Pandoc documents

plotTransform :: Pandoc -> IO Pandoc

Walk over an entire Pandoc document, changing appropriate code blocks into figures. Default configuration is used.

plotTransformWithConfig :: Configuration -> Pandoc -> IO Pandoc

Walk over an entire Pandoc document, changing appropriate code blocks into figures. The default values are determined by a Configuration.

Since: 2.1.0.0

For configuration purposes

configuration :: FilePath -> IO Configuration

Building configuration from a YAML file. The keys are exactly the same as for Markdown code blocks.

If a key is either not present or unreadable, its value will be set to the default value.

Since: 2.1.0.0

data Configuration

Configuration of pandoc-pyplot, describing the default behavior of the filter.

A Configuration is useful when dealing with lots of figures; it avoids repeating the same values.sta

Since: 2.1.0.0

Constructors

Configuration

Fields

• defaultDirectory :: FilePath

  The default directory where figures will be saved.

• defaultIncludeScript :: PythonScript

  The default script to run before other instructions.

• defaultSaveFormat :: SaveFormat

  The default save format of generated figures.

• defaultDPI :: Int

  The default dots-per-inch value for generated figures.

• interpreter :: String

  The name of the interpreter to use to render figures.

• flags :: [String]

  Command-line flags to be passed to the Python interpreger, e.g. ["-O", "-Wignore"]

Instances

Eq Configuration

Defined in Text.Pandoc.Filter.Pyplot.Types

Methods

(==) :: Configuration -> Configuration -> Bool

(/=) :: Configuration -> Configuration -> Bool

Show Configuration

Defined in Text.Pandoc.Filter.Pyplot.Types

Methods

showsPrec :: Int -> Configuration -> ShowS

show :: Configuration -> String

showList :: [Configuration] -> ShowS

Default Configuration

Defined in Text.Pandoc.Filter.Pyplot.Types

Methods

def :: Configuration

type PythonScript = Text

String representation of a Python script

data SaveFormat

Generated figure file format supported by pandoc-pyplot.

Constructors

PNG

PDF

SVG

JPG

EPS

GIF

TIF

Instances

Bounded SaveFormat

Defined in Text.Pandoc.Filter.Pyplot.Types

Methods

minBound :: SaveFormat

maxBound :: SaveFormat

Enum SaveFormat

Defined in Text.Pandoc.Filter.Pyplot.Types

Methods

succ :: SaveFormat -> SaveFormat

pred :: SaveFormat -> SaveFormat

toEnum :: Int -> SaveFormat

fromEnum :: SaveFormat -> Int

enumFrom :: SaveFormat -> [SaveFormat]

enumFromThen :: SaveFormat -> SaveFormat -> [SaveFormat]

enumFromTo :: SaveFormat -> SaveFormat -> [SaveFormat]

enumFromThenTo :: SaveFormat -> SaveFormat -> SaveFormat -> [SaveFormat]

Eq SaveFormat

Defined in Text.Pandoc.Filter.Pyplot.Types

Methods

(==) :: SaveFormat -> SaveFormat -> Bool

(/=) :: SaveFormat -> SaveFormat -> Bool

Show SaveFormat

Defined in Text.Pandoc.Filter.Pyplot.Types

Methods

showsPrec :: Int -> SaveFormat -> ShowS

show :: SaveFormat -> String

showList :: [SaveFormat] -> ShowS

For testing and internal purposes only

data PandocPyplotError

Possible errors returned by the filter

Constructors

ScriptError Int

Running Python script has yielded an error

ScriptChecksFailedError String

Python script did not pass all checks

Instances

Eq PandocPyplotError

Defined in Text.Pandoc.Filter.Pyplot.Types

Methods

(==) :: PandocPyplotError -> PandocPyplotError -> Bool

(/=) :: PandocPyplotError -> PandocPyplotError -> Bool

Show PandocPyplotError

Defined in Text.Pandoc.Filter.Pyplot.Types

Methods

showsPrec :: Int -> PandocPyplotError -> ShowS

show :: PandocPyplotError -> String

showList :: [PandocPyplotError] -> ShowS

makePlot' :: Configuration -> Block -> IO (Either PandocPyplotError Block)

Main routine to include Matplotlib plots. Code blocks containing the attributes .pyplot are considered Python plotting scripts. All other possible blocks are ignored.