How can I plot NaN values as a special color with imshow in Matplotlib?

Matplotlib Server Side Programming Programming

First, we can create an array matrix with some np.nan value, and using imshow method, we can create a diagram for that matrix.

Steps

Create a new figure, or activate an existing figure.
Add an `~.axes.Axes` to the figure as part of a subplot arrangement, nrows = 1, ncols = 1, index = 1.
Create a 2D array with np.nan.
Display data as an image, i.e., on a 2D regular raster.
Use the draw() method which draws the drawing at the given location.
To show the figure, use the plt.show() method.

Example

import numpy as np
import matplotlib.pyplot as plt

f = plt.figure()
ax = f.add_subplot(111)
a = [
      [1, 3, 5, np.nan, 8, 9, np.nan],
      [11, 13, 51, 71, 18, 19, 10],
      [11, 31, 51, 71, 81, 91, 10],
      [10, 30, 50, 70, np.nan, np.nan, np.nan],
      [np.nan, 3, 5, np.nan, 8, 9, np.nan]
   ]
ax.imshow(a, interpolation='nearest', vmin=0, vmax=24)
f.canvas.draw()
plt.show()

Output

Rishikesh Kumar Rishi

Published on 16-Mar-2021 10:39:13

Previous Page Print Page