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This tutorial shows how to draw a grid on a plot in Python Matplotlib. We will use grid()the function to achieve this. It also shows how to use grid()the function parameters to customize the color and shape of the grid, or even draw only vertical or horizontal lines.

Plotting a Normal Distribution in Matplotlib

Let's first create two lists to represent the x and y values ​​and use them to draw a graph. Call plot()the function and pass the x and y lists as parameters, then call show()the function.

Use the title(), , xlabeland ylabel()functions to add titles and labels to your plots to make them easier to understand.

from matplotlib import pyplot as plt

x = [10, 20, 30, 40, 50, 60, 70, 80, 90, 100, 110]
y = [200, 300, 300, 350, 380, 450, 500, 500, 520, 525, 530]

plt.title("MyPlot")
plt.xlabel("X Axis")
plt.ylabel("Y Axis")

plt.plot(x, y)
plt.show()

However, plain drawings seem boring and missing something. Now, we need to add a grid to our drawing.

Use in Matplotlib plotsgrid()

We will use the Matplotlib grid()function to draw a grid on the graph.

We need to show()call grid()the function before , so that a grid will be drawn on the previous figure.

Please see the code below.

from matplotlib import pyplot as plt

x = [10, 20, 30, 40, 50, 60, 70, 80, 90, 100, 110]
y = [200, 300, 300, 350, 380, 450, 500, 500, 520, 525, 530]

plt.title("MyPlot")
plt.xlabel("X Axis")
plt.ylabel("Y Axis")

plt.plot(x, y)
plt.grid()
plt.show()

Changing grid properties in Matplotlib

grid()The function accepts parameters to customize the color and style of the grid. We can grid(color='r', linestyle='dotted', linewidth=1)call it like this grid()to get a red grid with dots and thin lines.

from matplotlib import pyplot as plt

x = [10, 20, 30, 40, 50, 60, 70, 80, 90, 100, 110]
y = [200, 300, 300, 350, 380, 450, 500, 500, 520, 525, 530]

plt.title("MyPlot")
plt.xlabel("X Axis")
plt.ylabel("Y Axis")

plt.plot(x, y)
plt.grid(color="r", linestyle="dotted", linewidth=1)
plt.show()

Line width is a float data type and here are all the color codes and line styles for you to choose from.

Valid color codes.

Valid row format.

• -
• --
• -.
• :
• None
•  
• ``
• solid
• dashed
• dashdot
• dotted

Draw a vertical or horizontal line

grid()The default for the function is to draw both the horizontal and vertical axes, but you may want to customize this. You can axisdo this using the parameter. grid()When calling , use the default options to draw axis='x'only vertical lines, axis='y'only horizontal lines, or axis='both'both.

Please see the following code and its output.

from matplotlib import pyplot as plt

x = [10, 20, 30, 40, 50, 60, 70, 80, 90, 100, 110]
y = [200, 300, 300, 350, 380, 450, 500, 500, 520, 525, 530]

_, (a, b, c) = plt.subplots(1, 3)

a.grid(axis="y", linestyle="dotted", color="b")
a.plot(x, y)
a.set_title("axis='y'")

b.grid(axis="x", linestyle="dotted", color="b")
b.plot(x, y)
b.set_title("axis='x'")

c.grid(axis="both", linestyle="dotted", color="b")
c.plot(x, y)
c.set_title("axis='both'")

plt.show()