Matplotlib is a library in Python and it is numerical – mathematical extension for NumPy library. Pyplot is a state-based interface to a Matplotlib module which provides a MATLAB-like interface.
matplotlib.pyplot.pcolormesh() Function:
The pcolormesh() function in pyplot module of matplotlib library is used to create a pseudocolor plot with a non-regular rectangular grid.
Syntax:
matplotlib.pyplot.pcolormesh(\*args, alpha=None, norm=None, cmap=None, vmin=None, vmax=None, shading='flat', antialiased=False, data=None, \*\*kwargs)Parameters: This method accept the following parameters that are described below:
- C : This parameter contains the values in 2D array which are to be color-mapped.
- X, Y: These parameter are the coordinates of the quadrilateral corners.
- cmap : This parameter is a colormap instance or registered colormap name.
- norm : This parameter is the Normalize instance scales the data values to the canonical colormap range [0, 1] for mapping to colors
- vmin, vmax : These parameter are optional in nature and they are colorbar range.
- alpha : This parameter is a intensity of the color.
- snap : This parameter is used to snap the mesh to pixel boundaries.
- edgecolors : This parameter is the color of the edges. {‘none’, None, ‘face’, color, color sequence}
- shading : This parameter is the fill style. It can be flat or gouraud.
Returns: This returns the following:
- mesh : This returns the matplotlib.collections.QuadMesh
Below examples illustrate the matplotlib.pyplot.pcolormesh() function in matplotlib.pyplot: Example #1:
Python3
# Implementation of matplotlib functionimport matplotlib.pyplot as pltimport numpy as npfrom matplotlib.colors import LogNorm Z = np.random.rand(25, 25) plt.pcolormesh(Z)plt.title('matplotlib.pyplot.pcolormesh() function Example', fontweight ="bold")plt.show() |
Output: 
Example #2:
Python3
# Implementation of matplotlib functionimport matplotlib.pyplot as pltimport numpy as npfrom matplotlib.colors import LogNorm dx, dy = 0.015, 0.05y, x = np.mgrid[slice(-4, 4 + dy, dy), slice(-4, 4 + dx, dx)]z = (1 - x / 3. + x ** 6 + y ** 3) * np.exp(-x ** 2 - y ** 2)z = z[:-1, :-1]z_min, z_max = -np.abs(z).max(), np.abs(z).max() c = plt.pcolormesh(x, y, z, cmap ='Greens', vmin = z_min, vmax = z_max)plt.colorbar(c)plt.title('matplotlib.pyplot.pcolormesh() function Example', fontweight ="bold")plt.show() |
Output: 
