matlab绘图之title函数

title

Add title to axes or legend

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Syntax

• title(txt)
  example
• title(txt,Name,Value)
  example

• title(obj,___)
  example

• t = title(___)
  example

Description

example

title(txt) adds the specified title at the top and in the center of the current axes. Reissuing the title command causes the new title to replace the old title.

example

title(txt,Name,Value) additionally specifies title properties using one or more Name,Value pair arguments.

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title(obj,___) adds a title to the object specified by obj, instead of the current axes. Specify obj as either an axes object or a legend object. obj can precede any of the input argument combinations in the previous syntaxes.

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t = title(___) returns the object used as the title text. Use t to make future modifications to the title.

Examples

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Add Title to Current Figure

Open This Example

Create a figure and display a title in the current axes.

figure
plot((1:10).^2)
title('My Title')

You also can call title with a function that returns a string. For example, the date function returns a string containing today's date.

title(date)

MATLAB® sets the output of date as the axes title.

Include Variable's Value in Title

Open This Example

Include the value of variable c in a title.

figure
plot((1:10).^2)
f = 70;
c = (f-32)/1.8;
title(['Temperature is ',num2str(c),' C'])

Create Multicolored Title Using TeX Markup

Open This Example

In a TeX string, use the color modifier \color to change the color of characters following it from the previous color.

figure
plot((1:10).^2)
title(['\fontsize{16}black {\color{magenta}magenta '...
'\color[rgb]{0 .5 .5}teal \color{red}red} black again'])

Create Colored Title Using Name,Value Pair Argument

Open This Example

Use the Name,Value pair 'Color','m' to set the color of the title to magenta.

figure
plot((1:10).^2)
title('Case number # 3','Color', 'm')

Include Greek Symbols in Title

Open This Example

Use a TeX string to include Greek symbols in a title.

t = (0:0.01:0.2);
y = exp(-25*t);
figure
plot(t,y)
title('y = \ite^{\lambda t}','Color','b')

The 'Interpreter' property must be 'tex' (the default).

Include Superscript or Subscript Character in Title

Open This Example

figure
plot((1:10).^2)
title('\alpha^2 and X_1')

The superscript character, "^", and the subscript character, "_", modify the character or substring defined in braces immediately following.

Create Multiline Title

Open This Example

Create a multiline title using a multiline cell array.

figure
plot((1:10).^2)
title({'First line';'Second line'})

Display Text As Typed

Open This Example

Set the Interpreter property as 'none' so that the string X_1 is displayed in the figure as typed, without making 1 a subscript of X.

figure
plot((1:10).^2)
title('X_1','Interpreter','none')

MATLAB® displays the string X_1 in the title of the figure.

Add Title to Specific Axes

Open This Example

Create two subplots and return the handles to the axes objects, s(1) and s(2).

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

Add a title to each subplot by referring to its axes handle, s(1), or s(2).

title(s(1),'Top Plot')
title(s(2),'Bottom Plot')

Add Title and Return Text Handle

Open This Example

Add a title to a plot and return the text object.

plot((1:10).^2)
t = title('My Title');

Set the color of the title to red. Starting in R2014b, you can use dot notation to set properties. If you are using an earlier release, use the set function instead.

t.Color = 'red';

Input Arguments

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txt — Text to display as titlecharacter array | cell array | numeric value

Text to display as title, 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 title, 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 theInterpreter property.

To create multiline titles:

• 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 a line of text, such as ['abc'; 'ab ']. If you use this technique, each row must have the same number of characters.

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

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

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

obj — Target for titleaxes object | legend object

Target for title, specified as an axes object or a legend object. If you do not specify an object, then title adds the title 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',14 adds a title with red, 14-point font.

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

If you add a title to an axes object, then the font size properties for the axes also affect the title font size. The title font size updates to equal the axes font size multiplied by the title scale factor. The FontSize property of the axes contains the axes font size. The TitleFontSizeMultiplier property of the axes contains the scale factor. By default, the axes font size is 10 points and the scale factor is 1.1, so the title font size is 11 points.

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

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

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

• 'bold' — Thicker characters outlines than normal

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

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.

If you add a title to an axes object, then the TitleFontWeight property for the associated axes affects the FontWeight value for the title.

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 '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 'FixedWidth'. The 'FixedWidth' value relies on the root FixedWidthFontName property. Setting the rootFixedWidthFontName property causes an immediate update of the display to use the new font.

Example: 'Cambria'

'Color' — Text color[0 0 0] (default) | RGB triplet | character vector | 'none'

Text color, specified as a three-element RGB triplet, a character vector of a color name, or 'none'. The default color is black with an RGB triplet value of [0 0 0]. 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 the long and short color name options and the equivalent RGB triplet values.

Long Name	Short Name	RGB 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 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.

This table lists the supported modifiers with the Interpreter property set to 'tex'. Modifiers remain in effect until the end of the text. Superscripts and subscripts are an exception because they only modify the next character or the characters within the curly braces.

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 — 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 in point units 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 with the Interpreter property set to 'tex'.

Character Sequence	Symbol	Character Sequence	Symbol	Character Sequence	Symbol
\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	\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 property to 'latex'. Use dollar symbols around the text, for example, use '$\int_1^{20} x^2 dx$' for inline mode or'$$\int_1^{20} x^2 dx$$' for display mode.

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 more information about the LaTeX system, see The LaTeX Project website at http://www.latex-project.org/.

Output Arguments

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t — Object used for title texttext object

Object used for the title text, returned as one of these types of objects:

• Text object — If you add a title to axes, then title returns a text object. Use this text object to access and modify properties of the title after it is created. For a list of text object properties, see Text Properties. You also can access the title through the Title property of the axes object.

• Legend text object — If you add a title to a legend, then title returns a legend text object. Use this legend text object to access and modify properties of the title after it is created. For a list of legend text object properties, see Legend Text Properties. You also can access the title through the Title property of the legend object.

from: http://cn.mathworks.com/help/matlab/ref/title.html