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xlabel

Label x-axis

Description

example

xlabel(str) labels the x-axis of the current axes with the text specified by str. Reissuing the xlabel command replaces the old label with the new label.

example

xlabel(str,Name,Value) specifies text properties for the label using one or more Name,Value pair arguments. For example, 'Color','blue' creates a blue label.

example

xlabel(ax,___) adds the label to the axes specified by ax, instead of the current axes. The option ax can precede any of the input argument combinations in the previous syntaxes.

example

t = xlabel(___) returns the text object used as the x-axis label. Use t to make future modifications to the label after it is created.

Examples

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Label x-Axis

Display Population beneath the x-axis.

plot((1:10).^2)
xlabel('Population')


Create Multiline x-Axis Label

Create a multiline label using a cell array of strings.

plot((1:10).^2)
xlabel({'Population','(in thousands)'})


Include Greek Letters in x-Axis Label

Include Greek letters and other special characters in the label using TeX markup.

x = linspace(-2*pi,2*pi);
y = sin(x);
plot(x,y)
xlabel('-2\pi \leq x \leq 2\pi')


Include Variable Value in x-Axis Label

Add a label with text and a variable value. Use the num2str function to convert the variable value to a string.

plot((1:10).^2)
year = 2014;
xlabel(['Population for Year ',num2str(year)])


Include Superscript and Subscript in Axis Labels

Use the '^' and '_' characters to include superscripts and subscripts in the axis labels. Use curly braces {} to modify more than one character.

t = linspace(0,1);
y = exp(t);
plot(t,y)
xlabel('t_{seconds}')
ylabel('e^t')


Change x-Axis Label Font Size and Color

Use Name,Value pair arguments to set the font size, font weight, and text color properties of the x-axis label.

plot((1:10).^2)
xlabel('Population','FontSize',12,'FontWeight','bold','Color','r')


Label x-Axis of Specific Subplot

Create a figure with two subplots. Label the x-axis of the top subplot.

ax1 = subplot(2,1,1);
plot((1:10).^2)
xlabel(ax1,'Population')

ax2 = subplot(2,1,2);
plot((1:10).^3)


Modify x-Axis Label After Creation

Label the x-axis and return the text object used as the label.

plot((1:10).^2)
t = xlabel('Population');


Use t to set text properties of the label after it has been created. For example, set the color of the label to red.

t.Color = 'red';


Input Arguments

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str — Axis labelcharacter array | cell array | numeric value

Axis label, specified as a character array, cell array, or numeric value.

Example: 'my label'

Example: {'first line','second line'}

Example: 123

To include numeric variables with text in a label, use the num2str function. For example:

x = 42;
str = ['The value is',num2str(x)']

To include special characters, such as superscripts, subscripts, Greek letters, or mathematical symbols use TeX markup. For a list of supported markup, see the Interpreter property.

To create multiline labels:

• Use a cell array, where each cell contains a line of text, such as {'first line','second line'}.

• Use a character array, where each row contains the same number of characters, such as ['abc'; 'ab '].

• Use sprintf to create a string with a new line character, such as sprintf('first line \n second line').

 Note:   The words default, factory, and remove are reserved words that will not appear in a label when quoted as a normal string. To display any of these words individually, precede them with a backslash, such as '\default' or '\remove'.

ax — Axes objectaxes object

Axes object. If you do not specify an axes, then the xlabel function adds the label to the current axes.

Name-Value Pair Arguments

Specify optional comma-separated pairs of Name,Value arguments. Name is the argument name and Value is the corresponding value. Name must appear inside single quotes (' '). You can specify several name and value pair arguments in any order as Name1,Value1,...,NameN,ValueN.

Example: 'Color','red','FontSize',12 specifies red, 12-point font.

The text properties listed here are only a subset. For a complete list, see Text Properties.

'FontSize' — Font size11 (default) | scalar value greater than 0

Font size, specified as a scalar value greater than 0 in point units. One point equals 1/72 inch. To change the font units, use the FontUnits property.

Setting the font size properties for the associated axes also affects the label font size. The label font size updates to equal the axes font size times the label scale factor. The FontSize property of the axes contains the axes font size. The LabelFontSizeMultiplier property of the axes contains the label scale factor. By default, the axes font size is 10 points and the scale factor is 1.1, so the x-axis label font size is 11 points.

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

'FontWeight' — Thickness of text characters'normal' (default) | 'bold'

Thickness of the text characters, specified as one of these values:

• 'normal' — Default weight as defined by the particular font

• 'bold' — Thicker characters outlines than normal

MATLAB® uses the FontWeight property to select a font from those available on your system. Not all fonts have a bold font weight. Therefore, specifying a bold font weight could still result in the normal font weight.

 Note:   The 'light' and 'demi' font weight values have been removed. Use 'normal' instead.

'FontName' — Font name'Helvetica' (default) | 'FixedWidth' | system supported font name

Font name, specified as the name of the font to use or the string 'FixedWidth'. To display and print properly, the font name must be a font that your system supports.

To use a fixed-width font that looks good in any locale, use the case-sensitive string 'FixedWidth'. This eliminates the need to hard-code the name of a fixed-width font, which might not display text properly on systems that do not use ASCII character encoding. The 'FixedWidth' value relies on the root FixedWidthFontName property. Setting the root FixedWidthFontName property causes an immediate update of the display to use the new font.

Example: 'Cambria'

'Color' — Text color[0.15 0.15 0.15] (default) | RGB triplet | color string | 'none'

Text color, specified as a three-element RGB triplet, a color string, or 'none'. If you set the color to 'none', then the text is invisible.

An RGB triplet is a three-element row vector whose elements specify the intensities of the red, green, and blue components of the color. The intensities must be in the range [0,1], for example, [0.4 0.6 0.7]. This table lists RGB triplet values that have equivalent color strings.

Long NameShort NameRGB Triplet
'yellow''y'[1 1 0]
'magenta''m'[1 0 1]
'cyan''c'[0 1 1]
'red''r'[1 0 0]
'green''g'[0 1 0]
'blue''b'[0 0 1]
'white''w'[1 1 1]
'black'k'[0 0 0]

Example: 'blue'

Example: [0 0 1]

'Interpreter' — Interpretation of text characters'tex' (default) | 'latex' | 'none'

Interpretation of text characters, specified as one of these values:

• 'tex' — Interpret text strings using a subset of TeX markup. This is the default value.

• 'latex' — Interpret text strings using LaTeX markup.

• 'none' — Display literal characters.

TeX Markup

By default, MATLAB supports a subset of TeX markup. Use TeX markup to add superscripts and subscripts, modify the text type and color, and include special characters in the text string.

This table lists the supported modifiers when the Interpreter property is set to 'tex'. Modifiers remain in effect until the end of the string, except for superscripts and subscripts, which only modify the next character or the text within the curly braces {}.

ModifierDescriptionExample of String
^{ }Superscript'text^{superscript}'
_{ }Subscript'text_{subscript}'
\bfBold font'\bf text'
\itItalic font'\it text'
\slOblique font (usually the same as italic font)'\sl text'
\rmNormal font'\rm text'
\fontname{specifier}Font name — Set specifier as the name of a font family. You can use this in combination with other modifiers.'\fontname{Courier} text'
\fontsize{specifier}Font size — Set specifier as a numeric scalar value to change the font size.'\fontsize{15} text'
\color{specifier}Font color — Set specifer as one of these colors: red, green, yellow, magenta, blue, black, white, gray, darkGreen, orange, or lightBlue.'\color{magenta} text'
\color[rgb]{specifier}Custom font color — Set specifier as a three-element RGB triplet.'\color[rgb]{0,0.5,0.5} text'

This table lists the supported special characters when the interpreter is set to 'tex'.

Character SequenceSymbolCharacter SequenceSymbolCharacter SequenceSymbol

\alpha

α

\upsilon

υ

\sim

~

\angle

\phi

Φ

\leq

\ast

*

\chi

χ

\infty

\beta

β

\psi

ψ

\clubsuit

\gamma

γ

\omega

ω

\diamondsuit

\delta

δ

\Gamma

Γ

\heartsuit

\epsilon

ɛ

\Delta

Δ

\zeta

ζ

\Theta

Θ

\leftrightarrow

\eta

η

\Lambda

Λ

\leftarrow

\theta

Θ

\Xi

Ξ

\Leftarrow

\vartheta

ϑ

\Pi

Π

\uparrow

\iota

ι

\Sigma

Σ

\rightarrow

\kappa

κ

\Upsilon

ϒ

\Rightarrow

\lambda

λ

\Phi

Φ

\downarrow

\mu

µ

\Psi

Ψ

\circ

º

\nu

ν

\Omega

Ω

\pm

±

\xi

ξ

\forall

\geq

\pi

π

\exists

\propto

\rho

ρ

\ni

\partial

\sigma

σ

\cong

\bullet

\varsigma

ς

\approx

\div

÷

\tau

τ

\Re

\neq

\equiv

\oplus

\aleph

\Im

\cup

\wp

\otimes

\subseteq

\oslash

\cap

\in

\supseteq

\supset

\lceil

\subset

\int

\cdot

·

\o

ο

\rfloor

\neg

¬

\nabla

\lfloor

\times

x

\ldots

...

\perp

\surd

\prime

´

\wedge

\varpi

ϖ

\0

\rceil

\rangle

\mid

|

\vee

\langle

LaTeX Markup

To use LaTeX markup, set the Interpreter property to 'latex'. The displayed text uses the default LaTeX font style. The FontName, FontWeight, and FontAngle properties do not have an effect. To change the font style, use LaTeX markup within the text string.

The maximum size of the string that you can use with the LaTeX interpreter is 1200 characters. For multiline strings, this reduces by about 10 characters per line.

Output Arguments

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t — Text objecttext object

Text object used as the x-axis label. Use t to access and modify properties of the label after it has been created.