Positive angles in a graph

How can I have all positive angles in a graph, that I mean I have a graph plot(x,alfa) for example and all angles are positive, but one,180° is not positive, but negative in the graph, -180° and this messes up the graph, how can I do?

Answer 1

[KALYAN ACHARJYA]

%Force all angles must be positive.

mask=theta<0;
mask=360*double(mask);
theta=theta+mask;

[Andrea Cesaro]

Thank you