how i plot specified point from signal ?

how i plot specific point from signal, for example: i want to plot just the points that have y different to zero?

[KALYAN ACHARJYA]

Detail please?

[madhan ravi]

plot(y(y~=0),'+') % plots point other than y=0

[benarabi tarek]

madhan ravi, in this case index of the points where that have y not a zero appear in linear successive 1 2 3 4, but in reality 1, 6 ,7

[madhan ravi]

Please upload an example and your desired output so that it's clear you want to plot y against which parameter because if the x axis parameter is not defined then it's plotted against index.

[benarabi tarek]

I want to draw the points that have different "y" a zero and keep his index in the original

Answer 1

[Adam Danz]

If your data were plotted with

plot(x,y)

and you want to only plot data where y~=0, then first find the indices where y~=0 and eliminate them from both x and y.

yKeep = y~=0;
plot(x(yKeep), y(yKeep))

If you have data that are very close to 0 but not equal to zero (ie, 0.000001) and you want to eliminate them as well, use ismembertol().