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
# sample code import 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:
# Implementation of matplotlib function import matplotlib.pyplot as plt
import matplotlib.tri as mtri
import 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:
# Implementation of matplotlib function import matplotlib.pyplot as plt
import matplotlib.tri as tri
import numpy as np
n_angles = 26
n_radii = 10
min_radius = 0.35
radii = 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: