How Do You Plot a Cosine Function with a Unit Step in MATLAB?

[cleopatra]

Homework Statement

plot this function:
cos(pi*n)*u(n)

The Attempt at a Solution

n=0:1:10;
y=(n>=0);

x(n) = cos(pi()*n)*y

figure(1)
plot(y)

 

[rootX]

Homework Statement

plot this function:
cos(pi*n)*u(n)

The Attempt at a Solution

n=0:1:10;
y=(n>=0);

x(n) = cos(pi()*n)*y

figure(1)
plot(y)

y(t>=0)=1; ?

This should work ..
t=-2:0.1:2;
x=cos(pi()*t); x(t<=0)=0;
plot(t,x);

 

[cleopatra]

I don´t get what x(t<=0)=0 does ?
And where do you multiply the unit step function?
You wrote x=cos(pi()*t); but I can´t see where u(t) is...

 

[cleopatra]

nevermind I got it. thanks