Lesson 01: Introduction to MATLAB

Create a function handle to a named function:

fhandle = @myfunct

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,...)

Decimal point:

102.5543

Element-wise operations:

A .* B
A .^ B

Structure field access:

myStruct.f1

Object property specifier:

myObj.Property.Name

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;

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

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

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

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)

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)

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}
A = [A; 10 20 30]

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)

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

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

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

!rmdir oldtests

Retrieve the meta.class object for class inputParser:

?inputParser

Create a character vector:

chr = 'Hello, world'

Create a string scalar:

S = "Hello, world"

Separate row elements to create an array:

% These statements are equivalent
A = [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)

Separate rows in an array creation command:

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

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)

Separate rows in an array creation command:

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

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

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

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'])

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

cd ..\..\test

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

dir('january_*.mat')

Refer to a class folder:

\@myClass\get.m

Package folders always begin with the + character:

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