what do '--' and '-.' mean?

what do '--' and '-.' mean? I'm new to using Matlab, and I came across this while looking at some examples.

Answer 1

[Adam Danz]

These are line styles.

Also check out the LineSpec input to the plot function.

plot(X,Y,LineSpec)

[Estefania Garcia]

Thanks! Also do the values ([2:n]) mean?

where t = (0:160)';n = length(t);

[Adam Danz]

In the command window, type

help length

It tells you the length of t.

Now try

help :

Using the syntax 2:n, the colon operator counts from 2 and stop at or just before n by intervals of 1.

1.2 : 5

% ans = 
%    1.2          2.2          3.2          4.2

[Estefania Garcia]

Thank you!!