Matplotlib Tips and Examples

This is ongoing and constantly updated for new tips and tricks. While it is lightly organized, the main idea is as a dumping ground.

As of 2019-12-06, all examples are developed and tested with Python 3.6+ only. However, I will try to avoid using non-compatible syntax when I can.

I will also focus on the object-oriented interface falling back to pyplot (i.e. plt) when needed or to generate the figures

Preambles

All notebooks start with the following (though %matplotlib inline may be omitted at times)

import numpy as np
import matplotlib as mpl
import matplotlib.pylab as plt
%matplotlib inline 

import sys

print('Matplotlib Version: ' + mpl.__version__)
print('NumPy Version: ' + np.version.full_version)
print('Python Version: ' + sys.version)

import datetime
now  = datetime.datetime.now().isoformat()
print('Ran on ' + now)

Sections

• Fonts and Scientific Notation
• Subplots
• Ticks, Grids, Labels, and Legends
• Colorbars
• Line Colors
• Multiple Y-Axes
• 3D Plots: Contours and Surfaces
• Pathes and Hatches
• Inset Plots
• Bar Charts
• Scattered Data
• Scaled Colors
• Styles -- Custom and Built-in
• Visualizing Arrays
• Misc

Export Issues

By default, Jupyter exports images as png. In addition, at least with Chrome, only png can be viewed

Below is the command to export as PDF as well. However, markdown export tends to break (doesn't show images) when you do both exports. See workaround below

from IPython.display import set_matplotlib_formats
set_matplotlib_formats('png','pdf')  # Exports both png and pdf. See below for issues
set_matplotlib_formats('png') # Just pngs. Good for development

Markdown Export Workaround

As noted above, markdown export images do not work with the PDF option (though PDF export does work). The workaround is as follows:

1. Include the above code block, run the code, export as markdown
2. Remove the above code (or just have set_matplotlib_formats('png')), run the code, export to markdown
3. Find/Replace png) with pdf) and copy the corresponding pdf files into that directory

Changelog

• 2018-09-21 - Added color controls. Removed the function demo for pcolormesh since it didn't add anything. Added palette plots
• 2018-10-30 - Added my style and also updated how to remove an axis
• 2018-12-06 - Minor fix with regular bar charts. Added stacked. Noted python 2 vs 3
• 2019-12-06 - Reworked into multiple notebooks