Defining the midpoint of a colormap in Matplotlib

MatplotlibServer Side ProgrammingProgramming

Using plt.subplots(1, 1) method, we can create fig and axis. We can use fig.colorbar to make the color bar at the midpoint of the figure.

Steps

  • Using mgrid() method, `nd_grid` instance which returns an open multi-dimensional "meshgrid".

  • Create Z1, Z2 and Z data.

  • Create fig and ax variables using subplots method, where default nrows and ncols are 1, using subplots() method.

  • Create a colorbar for a ScalarMappable instance, *mappable*, using colorbar() method.

  • Using plt.show(), we can show the figure.

Example

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

N = 100
X, Y = np.mgrid[-3:3:complex(0, N), -2:2:complex(0, N)]

Z1 = np.exp(-(X)**2 - (Y)**2)
Z2 = np.exp(-(X * 10)**2 - (Y * 10)**2)
Z = Z1 + 50 * Z2

fig, ax = plt.subplots(1, 1)

fig.colorbar(ax.pcolor(X, Y, Z, norm=colors.LogNorm(vmin=Z.min(),
vmax=Z.max()), shading='auto'))
plt.show()

Output

raja
Published on 16-Mar-2021 09:55:10
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