# Find zeros of numeric function

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KostasK on 29 Nov 2019
Commented: ME on 29 Nov 2019
Hi all,
I have a numeric function which for the sake of simplicity resembles the following:
x = linspace(1:100) ;
y = sin(x) ;
I would like to know if there is a function in matlab where it returns the zeros of the above (presumably based on the sign change of adjacent elements).
KR,
KMT.
EDIT: The function as I say above is numeric, hence cannot be analitically expressed (i.e. sin cosing or whatever) as it is shown in my example. I used the above example just to create to numeric vectors.

ME on 29 Nov 2019
You could use fzero for this. Only issue is that it returns the zero closest to a chosen start point, therefore I've put a loop in to find multiple zeros. Maybe somebody could show a more elegant way?
fun = @sin;
x=linspace(1,100);
for i=1:numel(x)
x0(i)=fzero(fun,x(i));
end
x0=unique(x0)
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ME on 29 Nov 2019
Well then you could look at the below if you essentially just want to find the sign changes