Plot through bottom y-limit

How can I let a plot go through the bottm y-lim and connect to the next point at the oppisite (max) y-lim?

I have a x y matrix which y sapns from -180 to 180. Yet most of the data fluctuate around -180 and should then come back from the top of the plot rather than being connected going through 0.

Thanks.

Answer 1

[neil jerome]

not totally obvious what you mean. if you want to avoid the automatic joining of points through the x-axis that you want to sshow as 'wrapping' around over the axes limits (i assume the ±180 is a rotational thing), you can just plot another matched series one rotation 'higher', and fixing the y-limits will give the illusion of them being a single series.

% data that crosses -180
dat = [-163  -162  -172  -168  -186  -194  -169  -163  -144  -177  -168  -171  -189  -174  -168];
DAT = dat+360; % additional rotation data

figure; 
plot(1:15, dat, 'ro-'); % actual data will be clipped in figure < -180
hold on;
plot(1:15, DAT, 'bo-'); % colour just to show different series
ylim([-180 180]);

Answer 2

[Steven Lord]

If you want to make a "break" in your plot, include NaN in the X and/or Y vectors.

x = 0:0.25:10;
y = x.^2;

subplot(2, 1, 1)
plot(x, y)
title('No NaN values')

subplot(2, 1, 2)
y2 = y;
y2(mod(x, 1) == 0) = NaN;
plot(x, y2);
title('NaN values in y data for integer values of x')