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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

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