zlabel

Label z-axis

Syntax

zlabel(txt)

zlabel(txt,Name,Value)

zlabel(ax,___)

h = zlabel(___)

Description

zlabel(txt) labels the z-axis of the current axes with the text, txt. Reissuing the zlabel command causes the new label to replace the old label.

zlabel(txt,Name,Value) additionally specifies the text object properties using one or more Name,Value pair arguments.

zlabel(ax,___) adds the label to the axes specified by ax. This syntax allows you to specify the axes to which to add a label. ax can precede any of the input argument combinations in the previous syntaxes.

h = zlabel(___) returns the handle to the text object used as the z-axis label. The handle is useful when making future modifications to the label.

Examples

Label z-Axis

surf(peaks)
zlabel('Height')

Label z-Axis with Numeric Input

figure
surf(peaks)
zlabel(123)

MATLAB® displays 123 beside the z-axis.

Create Multiline z-Axis Label

Create a multiline label using a multiline cell array.

figure
surf(peaks)
zlabel({'First Line';'Second Line'})

Label z-Axis and Set Font Properties

Use Name,Value pairs to set the font size, font weight, and text color properties of the z-axis label.

figure
surf(peaks)
zlabel('Elevation','FontSize',12,...
       'FontWeight','bold','Color','r')

'FontSize',12 displays the label text in 12-point font. 'FontWeight','bold' makes the text bold. 'Color','r' sets the text color to red.

Label z-Axis of Specific Axes

Starting in R2019b, you can display a tiling of plots using the tiledlayout and nexttile functions. Call the tiledlayout function to create a 2-by-1 tiled chart layout. Call the nexttile function to create the axes objects ax1 and ax2. Create two surface plots, and add a z-axis label to the second plot by specifying ax2 as the first input argument to zlabel.

tiledlayout(2,1)
ax1 = nexttile;
surf(ax1,peaks(30))

ax2 = nexttile;
surf(ax2,peaks(45))
zlabel(ax2,'Height')

Label z-Axis and Return Object Handle

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

surf(peaks)
t = zlabel('Population Change');

Set the color of the label to red. Use dot notation to set properties.

t.Color = 'red';

Input Arguments

txt — Axis label

string scalar | character vector | string array | character array | cell array | categorical array | numeric value

Axis label, specified as a string scalar, character vector, string array, character array, cell array, categorical 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;
txt = ['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 string array, where each element contains a line of text, such as ["first line","second line"].

• 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 text with a new line character, such as sprintf('first line \n second line').

Numeric labels are converted to text using sprintf('%g',value). For example, 12345678 displays as 1.23457e+07.

Note

• If you specify the label as a categorical array, MATLAB^® uses the values in the array, not the categories.

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

ax — Target axes

Axes object | array of Axes objects

Target axes, specified as an Axes object or an array of Axes objects.

If you do not specify this argument, then zlabel modifies 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 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.

In addition to the following, you can specify other text object properties using Name,Value pair arguments. See Text Properties.

'FontSize' — Font size

11 (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 z-axis label font size is 11 points.

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

'FontWeight' — Character thickness

'normal' (default) | 'bold'

Character thickness, specified as 'normal' or 'bold'.

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

'FontName' — Font name

supported font name | 'FixedWidth'

Font name, specified as a supported font name or 'FixedWidth'. To display and print text properly, you must choose a font that your system supports. The default font depends on your operating system and locale.

To use a fixed-width font that looks good in any locale, use 'FixedWidth'. The fixed-width font relies on the root FixedWidthFontName property. Setting the root FixedWidthFontName property causes an immediate update of the display to use the new font.

'Color' — Text color

[0.15 0.15 0.15] (default) | RGB triplet | hexadecimal color code | 'r' | 'g' | 'b' | ...

Text color, specified as an RGB triplet, a hexadecimal color code, a color name, or a short name.

For a custom color, specify an RGB triplet or a hexadecimal color code.

• 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].

• A hexadecimal color code is a character vector or a string scalar that starts with a hash symbol (#) followed by three or six hexadecimal digits, which can range from 0 to F. The values are not case sensitive. Thus, the color codes '#FF8800', '#ff8800', '#F80', and '#f80' are equivalent.

Alternatively, you can specify some common colors by name. This table lists the named color options, the equivalent RGB triplets, and hexadecimal color codes.

Color Name	Short Name	RGB Triplet	Hexadecimal Color Code	Appearance
'red'	'r'	[1 0 0]	'#FF0000'
'green'	'g'	[0 1 0]	'#00FF00'
'blue'	'b'	[0 0 1]	'#0000FF'
'cyan'	'c'	[0 1 1]	'#00FFFF'
'magenta'	'm'	[1 0 1]	'#FF00FF'
'yellow'	'y'	[1 1 0]	'#FFFF00'
'black'	'k'	[0 0 0]	'#000000'
'white'	'w'	[1 1 1]	'#FFFFFF'
'none'	Not applicable	Not applicable	Not applicable	No color

Here are the RGB triplets and hexadecimal color codes for the default colors MATLAB uses in many types of plots.

RGB Triplet	Hexadecimal Color Code	Appearance
[0 0.4470 0.7410]	'#0072BD'
[0.8500 0.3250 0.0980]	'#D95319'
[0.9290 0.6940 0.1250]	'#EDB120'
[0.4940 0.1840 0.5560]	'#7E2F8E'
[0.4660 0.6740 0.1880]	'#77AC30'
[0.3010 0.7450 0.9330]	'#4DBEEE'
[0.6350 0.0780 0.1840]	'#A2142F'

Example: 'blue'

Example: [0 0 1]

Example: '#0000FF'

'Interpreter' — Text interpreter

'tex' (default) | 'latex' | 'none'

Text interpreter, specified as one of these values:

• 'tex' — Interpret characters using a subset of TeX markup.

• 'latex' — Interpret characters 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 font type and color, and include special characters in the text.

Modifiers remain in effect until the end of the text. Superscripts and subscripts are an exception because they modify only the next character or the characters within the curly braces. When you set the interpreter to 'tex', the supported modifiers are as follows.

Modifier	Description	Example
^{ }	Superscript	'text^{superscript}'
_{ }	Subscript	'text_{subscript}'
\bf	Bold font	'\bf text'
\it	Italic font	'\it text'
\sl	Oblique font (usually the same as italic font)	'\sl text'
\rm	Normal font	'\rm text'
\fontname{specifier}	Font name — Replace specifier with the name of a font family. You can use this in combination with other modifiers.	'\fontname{Courier} text'
\fontsize{specifier}	Font size —Replace specifier with a numeric scalar value in point units.	'\fontsize{15} text'
\color{specifier}	Font color — Replace specifier with 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 — Replace specifier with a three-element RGB triplet.	'\color[rgb]{0,0.5,0.5} text'

This table lists the supported special characters for the 'tex' interpreter.

Character Sequence	Symbol	Character Sequence	Symbol	Character Sequence	Symbol
\alpha	α	\upsilon	υ	\sim	~
\angle	∠	\phi		\leq	≤
\ast	*	\chi	χ	\infty	∞
\beta	β	\psi	ψ	\clubsuit	♣
\gamma	γ	\omega	ω	\diamondsuit	♦
\delta	δ	\Gamma	Γ	\heartsuit	♥
\epsilon	ϵ	\Delta	Δ	\spadesuit	♠
\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	ℜ	\neq	≠
\equiv	≡	\oplus	⊕	\aleph	ℵ
\Im	ℑ	\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	〈	\copyright	©

LaTeX Markup

To use LaTeX markup, set the interpreter to 'latex'. For inline mode, surround the markup with single dollar signs ($). For display mode, surround the markup with double dollar signs ($$).

LaTeX Mode	Example	Result
Inline	'$\int_1^{20} x^2 dx$'
Display	'$$\int_1^{20} x^2 dx$$'

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.

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

For examples that use TeX and LaTeX, see Greek Letters and Special Characters in Chart Text. For more information about the LaTeX system, see The LaTeX Project website at https://www.latex-project.org/.

Output Arguments

h — Text object

text object

Text object used as the z-axis label. Use h to access and modify properties of the label after its created.