Variable change with time interval

How can I create a code in matlab that changes the value of a Variable depending on the time interval?

For example different values of X as time progresses:

x=1 for 0<=t<900

x=2 for 900<=t<1800

X=3 for 1800<=t<=2700

X is my variable and t is time.

Answer 1

[Kevin Phung]

you can use if/else statements

example:

    if and(t >= 0, t < 900)
        x=1;
    elseif and(t>= 900, t<1800)
        x=2;
    elseif and(t >= 1800, t<= 2700)
        x=3;
    end