How to create a heat map in Python that ranges from green to red? (Matplotlib)

To create a heatmap in Python that ranges from green to red, we can take the following steps −

• Set the figure size and adjust the padding between and around the subplots.
• Make a dictionary for different colors.
• Create a colormap from linear mapping segments using LinearSegmentedColormap.
• Create a figure and a set of subplots.
• Create random data with 5☓5 dimension.
• Create a pseudocolor plot with a non-regular rectangular grid.
• Create a colorbar for a ScalarMappable instance, *mappable*.
• To display the figure, use show() method.

Example

import matplotlib.pyplot as plt
import matplotlib.colors as colors
import numpy as np

plt.rcParams["figure.figsize"] = [7.50, 3.50]
plt.rcParams["figure.autolayout"] = True

cdict = {'red': ((0.0, 0.0, 0.0),
                (0.5, 1.0, 1.0),
                (1.0, 1.0, 0.7)),

        'green': ((0.0, 0.7, 0.7),
                  (0.5, 1.0, 1.0),
                  (1.0, 0.0, 0.0)),

         'blue': ((0.0, 0.0, 0.0),
                  (0.5, 1.0, 1.0),
                  (1.0, 0.0, 0.0))
         }
GnRd = colors.LinearSegmentedColormap('GnRd', cdict)

fig, ax = plt.subplots(1)

data = np.random.rand(5, 5)*6.-3.

p = ax.pcolormesh(data, cmap=GnRd, vmin=-5, vmax=5)

fig.colorbar(p, ax=ax)

plt.show()

Output