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Add Title and Axis Labels to Chart

This example shows how to add a title and axis labels to a chart by using the title, xlabel, and ylabel functions. It also shows how to customize the appearance of the axes text by changing the font size.

Create Simple Line Plot

Create x as 100 linearly spaced values between -2π and 2π. Create y1 and y2 as sine and cosine values of x. Plot both sets of data.

x = linspace(-2*pi,2*pi,100);
y1 = sin(x);
y2 = cos(x);
figure
plot(x,y1,x,y2)

Figure contains an axes. The axes contains 2 objects of type line.

Add Title

Add a title to the chart by using the title function. To display the Greek symbol π, use the TeX markup, \pi.

title('Line Plot of Sine and Cosine Between -2\pi and 2\pi')

Figure contains an axes. The axes with title Line Plot of Sine and Cosine Between -2\pi and 2\pi contains 2 objects of type line.

Add Axis Labels

Add axis labels to the chart by using the xlabel and ylabel functions.

xlabel('-2\pi < x < 2\pi') 
ylabel('Sine and Cosine Values') 

Figure contains an axes. The axes with title Line Plot of Sine and Cosine Between -2\pi and 2\pi contains 2 objects of type line.

Add Legend

Add a legend to the graph that identifies each data set using the legend function. Specify the legend descriptions in the order that you plot the lines. Optionally, specify the legend location using one of the eight cardinal or intercardinal directions, in this case, 'southwest'.

legend({'y = sin(x)','y = cos(x)'},'Location','southwest')

Figure contains an axes. The axes with title Line Plot of Sine and Cosine Between -2\pi and 2\pi contains 2 objects of type line. These objects represent y = sin(x), y = cos(x).

Change Font Size

Axes objects have properties that you can use to customize the appearance of the axes. For example, the FontSize property controls the font size of the title, labels, and legend.

Access the current Axes object using the gca function. Then use dot notation to set the FontSize property.

ax = gca;
ax.FontSize = 13;

Figure contains an axes. The axes with title Line Plot of Sine and Cosine Between -2\pi and 2\pi contains 2 objects of type line. These objects represent y = sin(x), y = cos(x).

Title with Variable Value

Include a variable value in the title text by using the num2str function to convert the value to text. You can use a similar approach to add variable values to axis labels or legend entries.

Add a title with the value of sin(π)/2.

k = sin(pi/2);
title(['sin(\pi/2) = ' num2str(k)])

Figure contains an axes. The axes with title sin(\pi/2) = 1 contains 2 objects of type line. These objects represent y = sin(x), y = cos(x).

See Also

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