Matplotlib.axes.Axes.pcolor() in Python

Last Updated : 13 Apr, 2020

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.pcolor() Function

The Axes.pcolor() function in axes module of matplotlib library is also used to create a pseudocolor plot with a non-regular rectangular grid

Syntax: Axes.pcolor(self, *args, alpha=None, norm=None, cmap=None, vmin=None, vmax=None, data=None, **kwargs) pcolor([X, Y, ] C, **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.

edgecolors : This parameter is a ccolor of the edges. {'none', None, 'face', color, color sequence}

alpha : This parameter is a intensity of the color.

snap : This parameter is used to snap the mesh to pixel boundaries.

Returns: This returns the collection.

Below examples illustrate the matplotlib.axes.Axes.pcolor() function in matplotlib.axes: Example-1:

Python3

# Implementation of matplotlib function
import matplotlib.pyplot as plt
import numpy as np
from matplotlib.colors import LogNorm

Z = np.random.rand(6, 30)

fig, ax0 = plt.subplots()

ax0.pcolor(Z)

ax0.set_title('matplotlib.axes.Axes.pcolor() Examples')
plt.show()

Output:

Example-2:

Python3

# Implementation of matplotlib function
import matplotlib.pyplot as plt
import numpy as np
from matplotlib.colors import LogNorm

Z = np.random.rand(16, 30)

fig, (ax0, ax1) = plt.subplots(2, 1)

c = ax0.pcolor(Z)

c = ax1.pcolor(Z, edgecolors ='k', linewidths = 1)
ax1.set_title('2.Example with edges')

ax0.set_title('matplotlib.axes.Axes.pcolor() \
Examples\n1.Example with no edges')
plt.show()