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. There are various plots which can be used in Pyplot are Line Plot, Contour, Histogram, Scatter, 3D Plot, etc. Sample Code
Python3
# sample codeimport matplotlib.pyplot as plt plt.plot([1, 2, 3, 4], [16, 4, 1, 8]) plt.show() |
Output: 
matplotlib.pyplot.tricontour() Function
The tricontour() function in pyplot module of matplotlib library is used to draw contours on an unstructured triangular grid.
Syntax:
matplotlib.pyplot.tricontour(*args, **kwargs)Parameters: This method accept the following parameters that are described below:
- x, y: These parameter are the x and y coordinates of the data which is to be plot.
- triangulation: This parameter is a matplotlib.tri.Triangulation object.
- Z: This parameter is the array of values to contour, one per point in the triangulation.
- **kwargs: This parameter is Text properties that is used to control the appearance of the labels.
All remaining args and kwargs are the same as for matplotlib.pyplot. pcolor(). Returns: This returns the list of 2 Line2D containing following:
- The lines plotted for triangles edges.
- The markers plotted for triangles nodes
Below examples illustrate the matplotlib.pyplot.tricontour() function in matplotlib.pyplot: Example #1:
Python3
# Implementation of matplotlib functionimport matplotlib.pyplot as pltimport matplotlib.tri as mtriimport numpy as np # Create triangulation.x = np.asarray([0, 1, 2, 3, 0.5, 1.5, 2.5, 1, 2, 1.5])y = np.asarray([0, 0, 0, 0, 1.0, 1.0, 1.0, 2, 2, 3.0])triangles = [[0, 1, 4], [1, 5, 4], [2, 6, 5], [4, 5, 7], [5, 6, 8], [5, 8, 7], [7, 8, 9], [1, 2, 5], [2, 3, 6]]triang = mtri.Triangulation(x, y, triangles)z = np.cos(3 * x) * np.cos(6 * y)+np.sin(6 * x) fig, axs = plt.subplots()t = axs.tricontourf(triang, z)axs.tricontour(triang, z, colors ='white')fig.colorbar(t)fig.suptitle('matplotlib.pyplot.tricontour() Example') plt.show() |
Output: 
Example #2:
Python3
# Implementation of matplotlib functionimport matplotlib.pyplot as pltimport matplotlib.tri as triimport numpy as np n_angles = 26n_radii = 10min_radius = 0.35radii = np.linspace(min_radius, 0.95, n_radii) angles = np.linspace(0, 3 * np.pi, n_angles, endpoint = False)angles = np.repeat(angles[..., np.newaxis], n_radii, axis = 1)angles[:, 1::2] += np.pi / n_angles x = (10 * radii * np.cos(angles)).flatten()y = (10 * radii * np.sin(angles)).flatten()z = (np.cos(16 * radii) * np.cos(3 * angles)+np.sin(8 * radii)).flatten() triang = tri.Triangulation(x, y) triang.set_mask(np.hypot(x[triang.triangles].mean(axis = 1), y[triang.triangles].mean(axis = 1)) < min_radius) fig1, ax1 = plt.subplots()ax1.set_aspect('equal')tcf = ax1.tricontourf(triang, z)fig1.colorbar(tcf)ax1.tricontour(triang, z, colors ='k')fig1.suptitle('matplotlib.pyplot.tricontour() Example') plt.show() |
Output: 
