Matplotlib.axes.Axes.pcolormesh() in Python
Last Updated :
02 Nov, 2022
Matplotlib is a library in Python and it is numerical – mathematical extension for NumPy library. The Axes Class contains most of the figure elements: Axis, Tick, Line2D, Text, Polygon, etc., and sets the coordinate system. And the instances of Axes supports callbacks through a callbacks attribute.
matplotlib.axes.Axes.pcolormesh() Function
The Axes.pcolormesh() function in axes module of matplotlib library is also used to create a pseudocolor plot with a non-regular rectangular grid. It is more specialized than pcolor for the given purpose and thus is faster. It supports Gouraud shading
Syntax: Axes.pcolormesh(self, *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.axes.Axes.pcolormesh() function in matplotlib.axes:
Example-1:
Python3
import matplotlib.pyplot as plt
import numpy as np
from matplotlib.colors import LogNorm
Z = np.random.rand( 25 , 25 )
fig, ax0 = plt.subplots()
ax0.pcolormesh(Z)
ax0.set_title( 'matplotlib.axes.Axes.pcolormesh() Examples' )
plt.show()
|
Output:
Example-2:
Python3
import matplotlib.pyplot as plt
import numpy as np
from matplotlib.colors import LogNorm
dx, dy = 0.015 , 0.05
y, 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 ()
fig, ax = plt.subplots()
c = ax.pcolormesh(x, y, z, cmap = 'Greens' , vmin = z_min,
vmax = z_max)
fig.colorbar(c, ax = ax)
ax.set_title( 'matplotlib.axes.Axes.pcolormesh() Examples' )
plt.show()
|
Output:
Share your thoughts in the comments
Please Login to comment...