fontsize

Change font size for objects in a figure

Since R2022a

Syntax

fontsize(size,units)

fontsize("increase")

fontsize("decrease")

fontsize(scale=sfactor)

fontsize("default")

fontsize(obj,___)

Description

fontsize(size,units) sets the font size and font units for all of the text within the current figure. If the figure contains other graphics objects, such as UI components or an axes object with a legend, fontsize also sets the font size and font units for those objects in the figure. Font units can be "points", "pixels", "inches", or "centimeters".

Before R2023a: All syntaxes require a graphics object as the first input, such as fontsize(obj,size,units).

fontsize("increase") increases the font size by a factor of 1.1.

fontsize("decrease") decreases the font size by a factor of 0.9.

fontsize(scale=sfactor) scales the font size by a factor of sfactor. For example, use a scale factor of 1.2 to scale by 120%.

fontsize("default") resets the font size and font units to the default, automatic values.

fontsize(obj,___) sets the font size for all of the text within graphics object obj. If obj contains other graphics objects, fontsize also sets the font size for those objects. Specify obj as the first input argument in any of the previous syntaxes.

Examples

Change Font Size in Plot

Create a plot containing two lines with a title and a legend.

plot([0 1; 1 2])
title("Two Very Straight Lines")
legend("Blue Line","Red Line")

Increase the font size to 16 points.

fontsize(16,"points")

Before R2023a: Specify gcf as the first argument to the fontsize function. For example, fontsize(gcf,16,"points").

Scale Font Size of Text in Figure

Create a plot with several text elements of varying font sizes.

[X,Y,Z] = peaks;
contourf(X,Y,Z,LineColor="#4F4F4F")
title("Peak Elevation")
colorbar
annotation("textarrow",[.53 .41],[.65 .47],String="Local maxima")
annotation("textarrow",[.53 .59],[.65 .55])

Scale the font sizes in the figure by 120% by using a scale factor of 1.2. The fontsize function scales each font size individually, maintaining the relative sizes of the fonts.

fontsize(gcf,scale=1.2)

Change Font Size in Tiled Chart Layout

Create a tiling of several plots by using the tiledlayout and nexttile functions.

x = linspace(0,3*pi,200);
y = cos(x) + rand(1,200);
t = tiledlayout(2,2);

% Top scatter plot in tiles 1,2
ax1 = nexttile([1 2]);
scatter(x,y)
title("Random Variance on Cosine")

% Lower polar plot in tile 3
ax2 = nexttile;
plot(x,cos(x)+0.5)

% Lower histogram in tile 4
ax3 = nexttile;
histogram(y,20)

Scale up the font size of the scatter plot, and change the font size of the other two plots to 10 pixels.

fontsize(ax1,scale=1.2)
fontsize([ax2 ax3],10,"pixels")

To undo the font size changes across all the tiled plots, reset the font sizes and units to their default values. Apply this change to all three plots by using the current figure object returned by gcf.

fontsize(gcf,"default")

Change Font Size of App Text

Create the following function file, and save it as myapplayout.m on your MATLAB® path. This function returns the layout for a simple app to plot data using different plot types.

function fig = myapplayout
% Create figure window
fig = uifigure;

% Create UI components
ax = uiaxes(fig,Position=[15 70 535 340]);
lbl = uilabel(fig,Position=[30 15 100 35],Text="Choose Plot Type:");
b1 = uibutton(fig,Position=[140 15 180 35],Text="Surf");
b2 = uibutton(fig,Position=[350 15 180 35],Text="Mesh");

% Configure UI component appearance
surf(ax,peaks);
fontsize(fig,8,"pixels")
title(ax,"Peak Surface",FontSize=11)
end

Call the function and assign the returned figure object to f.

f = myapplayout;

Use f to increase the font size of all text in the figure until it is more easily readable. Here, the fontsize function increases each font size individually by a scale factor of 1.1, maintaining the relative sizes of the fonts.

fontsize(f,"increase")
fontsize(f,"increase")
fontsize(f,"increase")

Input Arguments

size — Font size

positive scalar value

Font size, specified as a positive scalar value.

Data Types: single | double | int8 | int16 | int32 | int64 | uint8 | uint16 | uint32 | uint64

units — Font size units

"points" | "pixels" | "inches" | "centimeters"

Font size units, specified as "points", "pixels", "inches", or "centimeters".

sfactor — Scale factor

scalar

Scale factor, specified as a scalar. All font sizes under the target object are scaled by sfactor. Use a scale factor greater than 1 to increase the font sizes or a factor less than 1 to decrease the font sizes.

Example: fontsize(gcf,scale=0.8) scales the text to 80% of its original size.

Data Types: single | double | int8 | int16 | int32 | int64 | uint8 | uint16 | uint32 | uint64

obj — Object or container with text

graphics object | array of graphics objects

Object or container with text, specified as a graphics object or array of graphics objects. The fontsize function sets the font size of text in the specified objects. If obj contains other graphics objects, such as a figure that contains UI components or an axes object that has a legend, the function also sets the font size and font units for those objects within obj. Objects without a FontSize property are not affected.

Version History

Introduced in R2022a

R2023a: Optionally omit objargument

You can optionally omit the obj argument when changing the font size of the current figure and its descendants.