Matlab → Basics → Variables in Matlab

Like all programming languages, we can declare variables in Matlab and can assign values to them. When a variable is given a value, that value is actually placed in the memory space assigned to the variable. Matlab shows all the declared variables and their values in the right column. For example, assign value 5 to variable *x*, 7 to variable *y*, and 12 to variable *z* and press * Enter*.

Figure: Assigning Values to Variables in Matlab

Now, suppose we have to find the value of when where , and . We can find it in the following way.

`>> x=20;`

>> y=11;

>> z=-3;

>> A=x+y+z

A =

28

`We can also write the above code in the following way.`

`>> x=20; y=11; z=-3;`

>> A=x+y+z

A =

28

Notice that if a semicolon is typed at the end of the command and * Enter* key is pressed, the Matlab stored the variable in the memory but does not display it. Besides, it is a good practice to declare all the variables on the same line.

**Example** Suppose $1,000 is deposited in a savings account that earns compounded interest at a rate of 10% per year. How much will be in the account after 2 years if interest is compounded:

(a) Monthly

(b) Weekly

**Solution**

**(a)** When interest is compounded monthly, the Matlab code is

`>> P=1000; r=0.1; t=2; n=12;`

>> A=P*(1+r/n)^(n*t)

A =

1220.39

**(b)** When interest is compounded weekly, the Matlab code is

`>> P=1000; r=0.1; t=2; n=52;`

>> A=P*(1+r/n)^(n*t)

A =

1221.17

**NOTE:** Matlab is case-sensitive, that means a≠A. Consider the following example,

`>> a=10; A=15; b=20; B=25;`

>> C=a+b

C =

30

`>> D=A+B`

D =

40