How can I find the indices where an array is closest to a certain value.

I have a periodic function stored as 'discrete' points in an array, and I need to find the indices of where they cross a certain point. I can't use == because they aren't ever equal (they would be if I was representing it continuously). Here's what I tried so far but it only detects some of the points.

Vc = .1; ERR = .012;

m = size(v); term = m(1,1);

c = 1;

for i = 2:term if v(i,1) >= Vc-ERR && v(i-1,1) <= Vc+ERR inds(c,1) = i; c = c+1; end end

Can someone suggest a better method?

Answer 1

[Honglei Chen]

This may be helpful to your problem

http://blogs.mathworks.com/pick/2007/06/20/zero-crossings-on-arbitrary-signals/

Answer 2

[Image Analyst]

How about

[minValue, minIndex] = min(abs(v - Vc));