MATLAB - Lecture 01 Introduction to (MATLAB Basics)

MATLAB Basics

Create a variable named a by typing this statement at the command line

>> a = 1

a =

1

Hide Result by adding (;) at end of statement.

>> a = 1;

When you do not specify an output variable, MATLAB uses the variable ans, short for answer, to store the results of your calculation.

>> sin(a)

ans =

0.8415

Built-in Functions:

>> d = cos(a)

d =

0.5403

Square root:

>> sqrt(36)

ans =

6

Complex Numbers

Complex numbers have both real and imaginary parts, where the imaginary unit is the square root of -1.

To represent the imaginary part of complex numbers, use either i or j .

>> sqrt(-1)

ans =

   0.0000 + 1.0000i

Workspace Variables

- MATLAB Is case-sensitive

The workspace contains variables that you create within or import into MATLAB from data files or other programs. For example, these statements create variables A and B in the workspace.

>> A = 9;

>> B = 10;

Workspace variables do not persist after you exit MATLAB. Save your data for later use with the save command.

   >> save C:\myfile.mat

Saving preserves the workspace in your current working folder in a compressed file with a .mat extension, called a MAT-file.

To clear all the variables from the workspace, use the clear command.

>> clear

Restore data from a MAT-file into the workspace using load.

>> load C:\myfile.mat

Text and Characters:

When you are working with text, enclose sequences of characters in single quotes. You can assign text to a variable.

>> myText = 'Hello, world';

• If the text includes a single quote, use two single quotes within the definition.

>> otherText = 'You''re right'

otherText =

'You're right'

You can concatenate character arrays with square brackets

>> longText = [myText,' - ',otherText]

longText =

'Hello, world - You're right'

To convert numeric values to characters, use functions, such as num2str or int2str.

>> f = 71;

>> c = (f-32)/1.8;

>> tempText = ['Temperature is ',num2str(c),'C']

tempText =

'Temperature is 21.6667C'

• Factorial of input

>> f = factorial(9)

f =

362880

• Absolute value and complex magnitude

>> y = abs(-9);

• Quotient of integer division

>> floor(23/5);

• remainder

>> rem(23,5);

>> mod(23,5);

• Integer Part

>> fix (23/5);

• Real nth root of real numbers

>> Y = nthroot(16,4);

• Is Prime numbers

>> isprime (5);

>> factor (30);

• Convert to Base System