https://github.com/dboyliao/matplotlib_notes

https://github.com/dboyliao/matplotlib_notes

Last synced: 8 days ago
JSON representation

• Host: GitHub
• URL: https://github.com/dboyliao/matplotlib_notes
• Owner: dboyliao
• Created: 2014-07-25T09:17:31.000Z (over 10 years ago)
• Default Branch: master
• Last Pushed: 2016-02-28T05:53:02.000Z (over 8 years ago)
• Last Synced: 2024-03-15T01:43:08.860Z (8 months ago)
• Language: Jupyter Notebook
• Size: 1.85 MB
• Stars: 0
• Watchers: 2
• Forks: 0
• Open Issues: 0
• Metadata Files:
  • Readme: README.md

Awesome Lists containing this project

README

        
# Notes for Matplolib

# Intro

There are four privmative drawing objects in `matplotlib`:

- `Line2D`: this object is used to present a 2D line on the graph or any other curves that can be Bezier-approximated.

- `AxesImage`: this object takes a 2D data and interprete it as densities with a colormap. This is usually returned by the `imshow` method.

- `Patch`: It represent a 2D object that has a single colored "face". This object must have "path" which is much like a Line2D object enclosing a a face to filled with that color.

- `Text`: It represent the text in a graph such as legends, labels,...etc. It takes a string, coordinates and font parameters to instantiate this object.

Any sophisticated plots in matplotlib are build upon these four objects. In the following notes, I will mostly use these four objects to plot all the graph. See the python scripts in `pracs` directory for more advanced examples.

Switch to `interative` branch to see how to write interative matplotlib applications.

# Events and Callback

## Line Picking

```{python}

import matplotlib.pyplot as plt

from matplotlib.collections import LineCollection

import numpy as np

import pickle

with open("../data/tracks.pickle") as pf:

    tracks = pickle.load(pf)

    tracks = dict((tid, t) for tid, t in tracks.items() if tid != -9)

fig, ax = plt.subplots(1, 1)

# Define th callback function.

# `event` obj has some useful attributes such as `x`, `y` (the `position`), `xdata` and `ydata` (the `value`).

def onpick_callback(event):

    if not isinstance(event.artist, LineCollection):

        return

    lws = event.artist.get_linewidths()

    print event.ind

    for i in event.ind:

        lws[i] = 4 if lws[i] != 4 else 1

    event.artist.set_linewidths(lws)

    fig.canvas.draw_idle()

    # `fig.canvas.draw_idle` is equivalent as `fig.canvas.draw` except the 

    # time when the drawing actually happen. `draw_idle` will wait in a queue

    # to be queued.

lc = LineCollection(tracks.values(), color = 'b', lw = [1 for _ in range(len(tracks))], picker = True)

ax.add_collection(lc)

ax.autoscale()

fig.canvas.mpl_connect('pick_event', onpick_callback)

ax.set_xlabel('Longitude')

ax.set_ylabel("Latitude")

plt.show()

```

## Drawing Span

# Interative Applications

# References

- [Matplotlib Doc.](http://matplotlib.org/users/index.html)

- [Mapplotlib Gallery](http://matplotlib.org/gallery.html)

- [Challenges](http://www.labri.fr/perso/nrougier/teaching/matplotlib/#d-plots)

- [Colormaps](http://matplotlib.org/users/colormaps.html)

- [Transformation](http://matplotlib.org/users/transforms_tutorial.html)

- [Bezier Curve](https://en.wikipedia.org/wiki/B%C3%A9zier_curve)

- [Patch Collections](http://matplotlib.org/examples/api/patch_collection.html)

- [3D subplots](http://matplotlib.org/examples/mplot3d/mixed_subplots_demo.html)

- [GridSpec](http://matplotlib.org/users/gridspec.html)

- [fig API](http://matplotlib.org/api/figure_api.html)

- [Matplotlib Collections](http://matplotlib.org/api/collections_api.html)