Matplotlib Tutorial

Matplotlib is a library to visualize the stuff you are interested in. It offers a number of different visualization tools ranging from simple 1d plots to interactive 3d colorful plots. This blog is still in development and contains the visualization techniques that at some point I’ve used. Whenever I learn a new technique, I will add that to here.

Installation

For conda users following command is good to go:

conda install -c conda-forge matplotlib

For old-school pip:

pip install matplotlib

Examples

In order to plot multiple images and use a common color bar, we can use the following codes. I’ve tried to explain every functionality I’ve used.

import numpy as np

import matplotlib

import matplotlib.pyplot as plt

import matplotlib.gridspec as gridspec

matplotlib.rc('text', usetex=False)

filters = np.random.randn(25,5,5)

min_weight = np.min(filters)

max_weight = np.max(filters)

fig, axes = plt.subplots(nrows=5, ncols=5, figsize=(7, 7))

for i, ax in enumerate(axes.flat):

ax.set_axis_off() # since I am plotting images, I don't want to see axis numbers.

im = ax.imshow(filters[i], cmap='viridis',

vmin=min_weight, vmax=max_weight)

fig.subplots_adjust(bottom=0.1, top=0.9, left=0.1, right=0.8,

wspace=0.04, hspace=0.04)

cb_ax = fig.add_axes([0.83, 0.1, 0.02, 0.8])

cbar = fig.colorbar(im, cax=cb_ax)

#set the colorbar ticks and tick labels

cbar.set_ticks(np.arange(min_weight, max_weight, (max_weight-min_weight-0.001)/2))

cbar.set_ticklabels([min_weight, (max_weight+min_weight)/2, max_weight])

plt.show()