Table of Contents
Matplotlib is a powerful tool used for creating visualizations in Python. One common task when creating plots is filling in the areas between lines. This can be achieved by using the “fill_between” function in Matplotlib. This function allows for filling in the space between two lines or between a line and the x-axis. By specifying the x and y values, along with optional parameters for color and transparency, users can easily fill in the areas between lines in their plots. This feature is useful for highlighting certain data points or creating shaded regions for comparison. With its simple syntax and customization options, filling in the areas between lines in Matplotlib is a convenient and effective way to enhance visualizations.
Fill in Areas Between Lines in Matplotlib
You can easily fill in the area between values in a Matplotlib plot by using following functions:
- fill_between(): Fill the area between two horizontal curves.
- fill_betweenx(): Fill the area between two vertical curves.
This tutorial provides examples of how to use each of these functions in practice.
Example 1: Fill in Area Between Two Horizontal Lines
The following code shows how to fill in the area between two horizontal lines:
import matplotlib.pyplotas plt import numpy as np #define x and y values x = np.arange(0,10,0.1) y = np.arange(10,20,0.1) #create plot of values plt.plot(x,y) #fill in area between the two lines plt.fill_between(x, y, color='red')
Note that we can also use the plt.grid() function to add gridlines to the plot to see the values that are being filled in more easily:
import matplotlib.pyplotas plt import numpy as np #define x and y values x = np.arange(0,10,0.1) y = np.arange(10,20,0.1) #create plot of values plt.plot(x,y) #fill in area between the two lines plt.fill_between(x, y, color='red', alpha=.5) #add gridlines plt.grid()
Example 2: Fill in Area Under a Curve
The following code show to fill in the area under a curve:
import matplotlib.pyplotas plt import numpy as np #define x and y values x = np.arange(0,10,0.1) y = x**4 #create plot of values plt.plot(x,y) #fill in area between the two lines plt.fill_between(x, y, color='red', alpha=.5)
Example 3: Fill in Area Above a Curve
The following code show to fill in the area above a curve:
import matplotlib.pyplotas plt import numpy as np #define x and y values x = np.arange(0,10,0.1) y = x**4 #create plot of values plt.plot(x,y) #fill in area between the two lines plt.fill_between(x, y, np.max(y), color='red', alpha=.5)
Example 4: Fill in Area Between Two Vertical Lines
The following code shows how to use the fill_betweenx() function to fill in the area between two vertical lines:
import matplotlib.pyplotas plt import numpy as np #define x and y values x = np.arange(0,10,0.1) y = np.arange(10,20,0.1) #create plot of values plt.plot(x,y) #fill in area between the two lines plt.fill_betweenx(y, 2, 4, color='red', alpha=.5)
