76. Matplotlib: Adding shaded areas to charts

plt.fill_between may be used to add shaded areas to charts. By using the alpha (transparency) argument shaded areas may overlap.

plot_29

import matplotlib.pyplot as plt

y1 = [60, 65, 65, 70, 75]
y1_max = [70, 73, 70, 78, 82]
y1_min = [55, 58, 61, 62, 68]

y2 = [45, 50, 55, 55, 55]
y2_max = [53, 55, 63, 60, 62]
y2_min = [35, 45, 52, 52, 50]

plt.plot(x, y1)
plt.plot(x, y2, linestyle ='dashed')

# alpha adjusts transparency, higher alpha --> darker grey
# Or color could be set to, for example '0.2', but using transparency allows
# overlapping shaded areas
plt.fill_between(x, y1_min, y1_max, color = 'k', alpha = 0.1)
plt.fill_between(x, y2_min, y2_max, color = 'k', alpha = 0.1)


plt.show()

 

50. Matplotlib: Adding contour lines to a heatmap

This post is also available as a PDF and as a Jupyter Notebook.

Here will will add contour lines to a heat map.

We’ll use something a little more interesting for the array of values, we’ll define a Mandlebrot fractal function. We have build a 1,000 and 1,000 array and calculate z as a Mandlebrot function of x and y.

The heatmap is drawn with plt.imshow, and then contour lines are added with plt.contour. Continue reading “50. Matplotlib: Adding contour lines to a heatmap”