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.contourf() Function
The Axes.contourf() function in axes module of matplotlib library is also used to plot contours. But contourfdraw filled contours, while contourf draws contour lines.
Syntax:
Axes.contourf(self, *args, data=None, **kwargs)Parameters: This method accept the following parameters that are described below:
- X, Y: These parameter are the coordinates of the values in Z.
- Z : This parameter is the height values over which the contour is drawn.
- levels : This parameter is used to determine the numbers and positions of the contour lines / regions.
Returns: This returns the following:
- c :This returns the QuadContourSet.
Below examples illustrate the matplotlib.axes.Axes.contourf() function in matplotlib.axes:
Example-1:
# Implementation of matplotlib function import numpy as np import matplotlib.pyplot as plt from numpy import ma from matplotlib import ticker, cm N = 1000x = np.linspace(-6.0, 6.0, N) y = np.linspace(-7.0, 7.0, N) X, Y = np.meshgrid(x, y) Z1 = np.exp(-(X)**2 - (Y)**2) z = 50 * Z1 z[:5, :5] = -1z = ma.masked_where(z <= 0, z) fig, ax = plt.subplots() cs = ax.contourf(X, Y, z, locator = ticker.LogLocator(), cmap ="Greens") cbar = fig.colorbar(cs) ax.set_title('matplotlib.axes.Axes.contourf() Example') plt.show() |
Output:
Example-2:
# Implementation of matplotlib function import matplotlib.pyplot as plt import numpy as np # invent some numbers, turning the # x and y arrays into simple 2d arrays, # which make combining them together easier. x = np.linspace(-3, 15, 450).reshape(1, -1) y = np.linspace(-3, 15, 720).reshape(-1, 1) z = np.cos(x)*2 - np.sin(y)**2 # we no longer need x and y to be # 2 dimensional, so flatten them. x, y = x.flatten(), y.flatten() fig1, ax1 = plt.subplots() cs = ax1.contourf(x, y, z, hatches =['-', '/', '\\', '//'], cmap ='Greens', extend ='both', alpha = 1) fig1.colorbar(cs) ax1.set_title('matplotlib.axes.Axes.contourf() Example') plt.show() |
Output:
