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.contour() Function
The Axes.contour() function in axes module of matplotlib library is used to Plot contours. contourdraw contour lines.
Syntax:
Axes.contour(self, *args, data=None, **kwargs) contour([X, Y, ] Z, [levels], **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.contour() function in matplotlib.axes:
Example-1:
# Implementation of matplotlib function import numpy as np import matplotlib.pyplot as plt import matplotlib.ticker as ticker import matplotlib delta = 0.15x = np.arange(-0.5, 2.5, delta) y = np.arange(-1.0, 3.0, delta) X, Y = np.meshgrid(x, y) Z = (np.exp(-X**2 - Y**2) - np.exp(-(X - 1)**2 - (Y - 1)**2)) fig1, ax1 = plt.subplots() CS1 = ax1.contour(X, Y, Z) fmt = {} strs = ['1', '2', '3', '4', '5', '6', '7'] for l, s in zip(CS1.levels, strs): fmt[l] = s ax1.clabel(CS1, CS1.levels, inline = True, fmt = fmt, fontsize = 10) ax1.set_title('matplotlib.axes.Axes.contour() Example') plt.show() |
Output:
Example-2:
# Implementation of matplotlib function import matplotlib import numpy as np import matplotlib.cm as cm import matplotlib.pyplot as plt delta = 0.25x = np.arange(-5.0, 5.0, delta) y = np.arange(-3.3, 5.5, delta) X, Y = np.meshgrid(x, y) Z = (np.exp(-X**2 - Y**2) - np.exp(-(X - 1)**2 - (Y - 1)**2)) * 3 fig, ax = plt.subplots() im = ax.imshow(Z, interpolation ='bilinear', origin ='lower', cmap ="Greens", extent =(-3, 3, -2, 2)) levels = np.arange(-1.2, 1.6, 0.2) CS = ax.contour(Z, levels, origin ='lower', cmap ='Blues', linewidths = 2, extent =(-3, 3, -2, 2)) zc = CS.collections[6] plt.setp(zc, linewidth = 4) ax.clabel(CS, levels, inline = 1, fmt ='% 1.1f', fontsize = 14) ax.set_title('matplotlib.axes.Axes.contour() Example') plt.show() |
Output:
