MATLAB Operators and Special Characters - MATLAB & Simulink (2024)

Addition

Unary plus

Subtraction

Unary minus

Element-wise multiplication

Matrix multiplication

Element-wise right division

Matrix right division

Element-wise left division

Matrix left division

(also known as backslash)

Element-wise power

Matrix power

Transpose

Complex conjugate transpose

Equal to

Not equal to

Greater than

Greater than or equal to

Less than

Less than or equal to

Find logical AND

Find logical OR

Find logical AND (with short-circuiting)

Find logical OR (with short-circuiting)

Find logical NOT

Name: At symbol

Uses:

Description: The @ symbol forms a handle to either the named function that follows the @ sign, or to the anonymous function that follows the @ sign. You can also use @ to call superclass methods from subclasses.

Examples

Create a function handle to a named function:

fhandle = @myfun

Create a function handle to an anonymous function:

fhandle = @(x,y) x.^2 + y.^2;

Call the disp method of MySuper from a subclass:

disp@MySuper(obj)

Call the superclass constructor from a subclass using the object being constructed:

obj = obj@MySuper(arg1,arg2,...)

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Name: Period or dot

Uses:

Description: The period character separates the integral and fractional parts of a number, such as 3.1415. MATLAB operators that contain a period always work element-wise. The period character also enables you to access the fields in a structure, as well as the properties and methods of an object.

Examples

Decimal point:

102.5543

Element-wise operations:

A.*BA.^2

Structure field access:

myStruct.f1

Object property specifier:

myObj.PropertyName

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Name: Dot dot dot or ellipsis

Uses: Line continuation

Description: Three or more periods at the end of a line continues the current command on the next line. If three or more periods occur before the end of a line, then MATLAB ignores the rest of the line and continues to the next line. This effectively makes a comment out of anything on the current line that follows the three periods.

Examples

Continue a function call on the next line:

sprintf(['The current value '...'of %s is %d'],vname,value)

Break a character vector up on multiple lines and concatenate the lines together:

S = ['If three or more periods occur before the '... 'end of a line, then the rest of that line is ' ... 'ignored and MATLAB continues to the next line']

To comment out one line in a multiline command, use ... at the beginning of the line to ensure that the command remains complete. If you use % to comment out a line it produces an error:

y = 1 +... 2 +... % 3 +... 4;

However, this code runs properly since the third line does not produce a gap in the command:

y = 1 +... 2 +...... 3 +... 4;

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Name: Comma

Uses: Separator

Description: Use commas to separate row elements in an array, array subscripts, function input and output arguments, and commands entered on the same line.

Examples

Separate row elements to create an array:

A = [12,13; 14,15]

Separate subscripts:

A(1,2)

Separate input and output arguments in function calls:

[Y,I] = max(A,[],2)

Separate multiple commands on the same line (showing output):

figure, plot(sin(-pi:0.1:pi)), grid on

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Name: Colon

Uses:

Description: Use the colon operator to create regularly spaced vectors, index into arrays, and define the bounds of a for loop.

Examples

Create a vector:

x = 1:10

Create a vector that increments by 3:

x = 1:3:19

Reshape a matrix into a column vector:

A(:)

Assign new elements without changing the shape of an array:

A = rand(3,4);A(:) = 1:12;

Index a range of elements in a particular dimension:

A(2:5,3)

Index all elements in a particular dimension:

A(:,3)

for loop bounds:

x = 1;for k = 1:25 x = x + x^2;end

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Name: Semicolon

Uses:

Description: Use semicolons to separate rows in an array creation command, or to suppress the output display of a line of code.

Examples

Separate rows to create an array:

A = [12,13; 14,15]

Suppress code output:

Y = max(A);

Separate multiple commands on a single line (suppressing output):

A = 12.5; B = 42.7, C = 1.25;B = 42.7000

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Name: Parentheses

Uses:

Description: Use parentheses to specify precedence of operations, enclose function input arguments, and index into an array.

Examples

Precedence of operations:

(A.*(B./C)) - D

Function argument enclosure:

plot(X,Y,'r*')C = union(A,B)

Indexing:

A(3,:)A(1,2)A(1:5,1)

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Name: Square brackets

Uses:

Description: Square brackets enable array construction and concatenation, creation of empty matrices, deletion of array elements, and capturing values returned by a function.

Examples

Construct a three-element vector:

X = [10 12 -3]

Add a new bottom row to a matrix:

A = rand(3);A = [A; 10 20 30]

Create an empty matrix:

A = []

Delete a matrix column:

A(:,1) = []

Capture three output arguments from a function:

[C,iA,iB] = union(A,B)

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Name: Curly brackets

Uses: Cell array assignment and contents

Description: Use curly braces to construct a cell array, or to access the contents of a particular cell in a cell array.

Examples

To construct a cell array, enclose all elements of the array in curly braces:

C = {[2.6 4.7 3.9], rand(8)*6, 'C. Coolidge'}

Index to a specific cell array element by enclosing all indices in curly braces:

A = C{4,7,2}

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Name: Percent

Uses:

Description: The percent sign is most commonly used to indicate nonexecutable text within the body of a program. This text is normally used to include comments in your code.

Some functions also interpret the percent sign as a conversion specifier.

Two percent signs, %%, serve as a cell delimiter as described in Create and Run Sections in Code.

Examples

Add a comment to a block of code:

% The purpose of this loop is to compute% the value of ...

Use conversion specifier with sprintf:

sprintf('%s = %d', name, value)

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Name: Percent curly bracket

Uses: Block comments

Description: The %{ and %} symbols enclose a block of comments that extend beyond one line.

Examples

Enclose any multiline comments with percent followed by an opening or closing brace:

%{The purpose of this routine is to computethe value of ... %}

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Name: Exclamation point

Uses: Operating system command

Description: The exclamation point precedes operating system commands that you want to execute from within MATLAB.

Not available in MATLAB Online™.

Examples

The exclamation point initiates a shell escape function. Such a function is to be performed directly by the operating system:

!rmdir oldtests

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Name: Question mark

Uses: Metaclass for MATLAB class

Description: The question mark retrieves the meta.class object for a particular class name. The ? operator works only with a class name, not an object.

Examples

Retrieve the meta.class object for class inputParser:

?inputParser

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Name: Single quotes

Uses: Character array constructor

Description: Use single quotes to create character vectors that have class char.

Examples

Create a character vector:

chr = 'Hello, world'

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Name: Double quotes

Uses: String constructor

Description: Use double quotes to create string scalars that have class string.

Examples

Create a string scalar:

S = "Hello, world"

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Name: Space character

Uses: Separator

Description: Use the space character to separate row elements in an array constructor, or the values returned by a function. In these contexts, the space character and comma are equivalent.

Examples

Separate row elements to create an array:

% These statements are equivalentA = [12 13; 14 15]A = [12,13; 14,15]

Separate output arguments in function calls:

% These statements are equivalent[Y I] = max(A)[Y,I] = max(A)

Name: Newline character

Uses: Separator

Description: Use the newline character to separate rows in an array construction statement. In that context, the newline character and semicolon are equivalent.

Examples

Separate rows in an array creation command:

% These statements are equivalentA = [12 13 14 15]A = [12 13; 14 15]

Name: Tilde

Uses:

Description: Use the tilde symbol to represent logical NOT or to suppress specific input or output arguments.

Examples

Calculate the logical NOT of a matrix:

A = eye(3);~A

Determine where the elements of A are not equal to those of B:

A = [1 -1; 0 1]B = [1 -2; 3 2]A~=B

Return only the third output value of union:

[~,~,iB] = union(A,B)

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Name: Equal sign

Uses: Assignment

Description: Use the equal sign to assign values to a variable. The syntax B = A stores the elements of A in variable B.

Examples

Create a matrix A. Assign the values in A to a new variable, B. Lastly, assign a new value to the first element in B.

A = [1 0; -1 0];B = A;B(1) = 200;

Name: Left angle bracket and ampersand

Uses: Specify superclasses

Description: Specify one or more superclasses in a class definition

Examples

Define a class that derives from one superclass:

classdef MyClass < MySuperclass …end

Define a class that derives from multiple superclasses:

classdef MyClass < Superclass1 & Superclass2 & … …end

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Name: Dot question mark

Uses: Specify fields of name-value structure

Description:

When using function argument validation, you can define the fields of the name-value structure as the names of all writeable properties of the class.

Examples

Specify the field names of the propArgs structure as the writeable properties of the matlab.graphics.primitive.Line class.

function f(propArgs) arguments propArgs.?matlab.graphics.primitive.Line end % Function code ...end

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/

\

Name: Slash and Backslash

Uses: File or folder path separation

Description: In addition to their use as mathematical operators, the slash and backslash characters separate the elements of a path or folder. On Microsoft^® Windows^® based systems, both slash and backslash have the same effect. On The Open Group UNIX^® based systems, you must use slash only.

Examples

On a Windows system, you can use either backslash or slash:

dir([matlabroot '\toolbox\matlab\elmat\shiftdim.m'])dir([matlabroot '/toolbox/matlab/elmat/shiftdim.m'])

On a UNIX system, use only the forward slash:

dir([matlabroot '/toolbox/matlab/elmat/shiftdim.m'])

Name: Dot dot

Uses: Parent folder

Description: Two dots in succession refers to the parent of the current folder. Use this character to specify folder paths relative to the current folder.

Examples

To go up two levels in the folder tree and down into the test folder, use:

cd ..\..\test

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Name: Asterisk

Uses: Wildcard character

Description: In addition to being the symbol for matrix multiplication, the asterisk * is used as a wildcard character.

Wildcards are generally used in file operations that act on multiple files or folders. MATLAB matches all characters in the name exactly except for the wildcard character *, which can match any one or more characters.

Examples

Locate all files with names that start with january_ and have a .mat file extension:

dir('january_*.mat')

Name: At symbol

Uses: Class folder indicator

Description: An @ sign indicates the name of a class folder.

Examples

Refer to a class folder:

\@myClass\get.m

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Name: Plus

Uses: Package directory indicator

Description: A + sign indicates the name of a package folder.

Examples

Package folders always begin with the + character:

+mypack+mypack/pkfcn.m % a package function+mypack/@myClass % class folder in a package

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Single quotation mark

Single percent sign

Single backslash

Alarm

Backspace

Form feed

New line

Carriage return

Horizontal tab

Vertical tab

Hexadecimal number, N

Octal number, N