In this article, you'll learn how to use markers in Matplotlib to indicate specific points in a plot.

The marker parameter can be used to create "markers" in a plot. You can specify the shape of the marker by passing a value to the parameter.

Here's what a normal Matplotlib plot looks like:

import matplotlib.pyplot as plt
import numpy as np

x = [2,4,6,8]
y = [1,3,9,7]

plt.plot(x,y)
plt.show()
plot-without-marker
a matplotlib plot without a marker

Here's a plot with a marker:

import matplotlib.pyplot as plt
import numpy as np

x = [2,4,6,8]
y = [1,3,9,7]

plt.plot(x,y, marker = 'o')
plt.show()
plot-with-markers
a matplotlib plot with an "o" marker

As can be seen in the image above, every meeting point for both axis in the plot is denoted by a marker that looks like an circle.

We're able to do that by setting the value of the marker parameter to "0": plt.plot(x,y, marker = 'o').

List of Matplotlib Markers

Here is a list (from the Matplotlib documentation) of marker values that can be assigned to the marker parameter:

Marker Description
"." point
"," pixel
"o" circle
"v" triangle_down
"^" triangle_up
"<" triangle_left
">" triangle_right
"1" tri_down
"2" tri_up
"3" tri_left
"4" tri_right
"8" octagon
"s" square
"p" pentagon
"P" plus (filled)
"h" hexagon1
"H" hexagon2
"+" plus
"*" star
"x" x
"X" x (filled)
"D" diamond
"d" thin_diamond
"_" hline
"s" square
0 tickleft
1 tickright
2 tickup
3 tickdown
4 caretleft
5 caretright
6 caretup
7 caretdown
8 caretleft (centered at base)
9 caretright (centered at base)
10 caretup (centered at base)
11 caretdown (centered at base)

This list above shows the different values you can use to change the style of a marker in a plot.

Summary

In this article, we talked about markers in Matplotlib. They can be used to mark/indicate specific points in a plot.

We saw some code examples showing the application of the marker parameter.

Lastly, we saw a list of marker values that can be used to change the style of a marker.

Happy coding!