MATLAB: How to plot lines as separated segments

Question

Hi all,

I have a signal and a need to highlight the portion of the signal which meets a specific condition. I have found two ways to accomplish it, plotting line or plotting markers. With line, I have the problem that joint segments (the horizontal segments in the plotted figure below) are created and this may seem that this segments are part of the dataset. On the other hand, with markers is graphically bad-looking, especially when there are abrupt changes in the signal. How can I make the plot on bottom with lines rather than markers?

Thank you

t=[0:0.01:10];
a=sin(2*pi*t);
figure
subplot(2,1,1)
plot(t,a)
hold on
plot(t(a>0.9),a(a>0.9))
title('with line')
subplot(2,1,2)
plot(t,a)
hold on
plot(t(a>0.9),a(a>0.9),'.')
title('with marker')

Answer 1

t2 = t;
a2 = a;
mask = a<=0.9;
t2(mask) =nan;
a2(mask) =nan;
plot(t2, a2);