Drawing a horizontal line in Matplotlib
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To draw a horizontal line in Matplotlib, use the axhline(~) function like so:
plt.axhline(y=0.5)
The output is as follows:
Changing the color
To change color of the line, add the color parameter:
color="red" color="#FF0000"
Changing the line style
To change the styling of the line, add the linestyle parameter:
linestyle="dotted"linestyle="dashed"
Specifying the starting and endpoint points
By default, the line drawn by axhline(~) spans the entire width of the graph.
xmin and xmax
You could change this behavior by specifying parameters xmin and xmax, both of which must be a number between 0 and 1.Here, 0 represents the left-side of your graph, while 1 represents the right-side of your graph.
To draw a horizontal line from left 25% to right 75%:
plt.xlim(0, 10)plt.axhline(y=2, xmin=0.25, xmax=0.75)
The output is as follows:
x-coordinates
Unfortunately, the axhline(~) method does not accept starting and ending x-coordinates. We can instead resort to the plt.plot(~) function, which does allow for x-coordinates.
To draw a horizontal line from x=2 to x=8 at y=5:
plt.xlim(0, 10)plt.plot([2,8], [5,5])
The output is as follows:
