matrix index in matlab code example

Example 1: matlab matrix index

A = [16 5 9; 4 2 11; 7 14 9]; % Create matrix

A(2,3)   % Extract the element in row 2, column 3
ans = 11

A(1:2,2:3) % Extract elements in rows 1 and 2, and columns 2 and 3
ans = 	5	9
		2	11

Example 2: matlab array indexing

Indicating indexes between ([]) retrieves corresponding values in Matlab. 
array_borders=array([1 end])
As end defines size of the array, retrieve first and last border values of array
even_values=array(2:2:end)
Retrieve only second elements of array, from secon with 2 step iteration 
increase until end of array.
first_3_values=array(1:3)
Retrieve only first 3 elements of array.