Page 15 - Basics of MATLAB and Beyond

1.3 Matrices
The basic object that matlab deals with is a matrix. A matrix is an
array of numbers. For example the following are matrices:

 
  i
12 3 9
 −i 
 −1200 0 1e6  , 12345 ,   , 42.
 i 
0.1 pi 1/3
−i
The size of a matrix is the number of rows by the number of columns.
The first matrix is a 3×3 matrix. The (2,3)-element is one million—1e6
6
stands for 1 × 10 —and the (3,2)-element is pi = π =3.14159 ... .
The second matrix is a row-vector, the third matrix is a column-vector
containing the number i, which is a pre-defined matlab variable equal
to the square root of −1. The last matrix is a 1 × 1 matrix, also called
a scalar.

1.4 Variables
Variables in matlab are named objects that are assigned using the
equals sign = . They are limited to 31 characters and can contain
upper and lowercase letters, any number of ‘_’ characters, and numer-
als. They may not start with a numeral. matlab is case sensitive: A
and a are different variables. The following are valid matlab variable
assignments:
a=1
speed = 1500
BeamFormerOutput_Type1 = v*Q*v’
name = ’John Smith’
These are invalid assignments:
2for1 = ’yes’
first one = 1
To assign a variable without getting an echo from matlab end the
assignment with a semi-colon ;. Try typing the following:
a=2
b=3;
c = a+b;
d = c/2;
d
who
whos
clear
who

c 2000 by CRC Press LLC