Plotting a piecewise continuous function

Question

I would like to plot a piecewise function that is not continuous using the following code. However, the output always appears a continuous function, as MATLAB joins the gaps between these sub-functions.

i1 = -2:0;
i2 = 0:pi/2;
i3 = pi/2:pi;
f1 = sinh(i1)+2;
f2 = sin(i2)-2;
f3= 2*i3.^2-2*pi*i3+3;
plot([i1 i2 i3],[f1,f2,f3]);

How should I resolve this problem in a not-so-complicated way?

PS. I am using MATLAB 2013a, it seems that the function piecewise doesn't exist in this version.

Answer 1

Add nan between the functions, that'll disjoin them:

i1 = -2:0;
i2 = 0:pi/2;
i3 = pi/2:pi;
f1 = sinh(i1)+2;
f2 = sin(i2)-2;
f3= 2*i3.^2-2*pi*i3+3;
plot([i1 nan i2 nan i3],[f1,nan,f2,nan,f3]);

The other option, resulting in the same graph, is to plot all three of them separately using hold on :

figure;
hold on
plot(i1,f1,'b');
plot(i2,f2,'b');
plot(i3,f3,'b');

Or use the plot(X,Y,X1,Y1,...,Xn,Yn syntax:

figure;
plot(i1,f1,'b',i2,f2,'b',i3,f3,'b')

Note that for the latter two you must specify the line style, so as to prevent MATLAB from making them separate colours, hence the 'b' .