Question

I have a single dimensional array of floating point values (c# doubles FYI) and I need to find the “peak” of the values … as if graphed.

I can’t just take the highest value, as the peak is actually a plateau that has small fluctuations. This plateau is in the middle of a bunch of noise. I’m looking find a solution that would give me the center of this plateau.

An example array might look like this:

1,2,1,1,2,1,3,2,4,4,4,5,6,8,8,8,8,7,8,7,9,7,5,4,4,3,3,2,2,1,1,1,1,1,2,1,1,1,1

where the peak is somewhere in the bolded section.

Any ideas?

Answer 1

You need to first define what you mean by ‘small’. Say, ‘small’ fluctuation around the maximum is defined as any value that is within ± ϵ of the maximum. Then, it is straightforward to identify the plateau.

Pass through the data to identify the maximum and then do a second pass to identify all values that are within ± ϵ of the maximum.