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.pcolorfast() Function
The Axes.pcolorfast() function in axes module of matplotlib library is also used to create a pseudocolor plot with a non-regular rectangular grid.It has some limitations : supports only flat shading, lack of log scaling and lack of pyplot wrapper.
Syntax: Axes.pcolorfast(self, *args, alpha=None, norm=None, cmap=None, vmin=None, vmax=None, data=None, **kwargs)
pcolorfast([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.
- 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 following:
- image: This returns the image depend on AxesImage, PcolorImage and QuadMesh .
Below examples illustrate the matplotlib.axes.Axes.pcolorfast() function in matplotlib.axes:
Example-1:
# Implementation of matplotlib function import matplotlib.pyplot as plt import numpy as np from matplotlib.colors import LogNorm Z = np.random.rand(30, 30) fig, ax0 = plt.subplots() ax0.pcolorfast(Z) ax0.set_title('matplotlib.axes.Axes.pcolorfast() Examples') plt.show() |
Output:
Example-2:
# Implementation of matplotlib function import matplotlib.pyplot as plt import numpy as np from matplotlib.colors import LogNorm dx, dy = 0.15, 0.05y, x = np.mgrid[slice(-3, 3 + dy, dy), slice(-3, 3 + dx, dx)] z = (1 - x / 2. + x ** 5 + 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.pcolorfast(x, y, z, cmap ='Greens', vmin = z_min, vmax = z_max) fig.colorbar(c, ax = ax) ax.set_title('matplotlib.axes.Axes.pcolorfast() Examples') plt.show() |
Output:
