Knowing the presence of a peak around a point

How to know wheather a peak is present around a ponint 'x0' in a 1d plot.

Clearly saying I want to know wheather a peak is present in the space 'x0-d' to 'x0+d' where d is a variable representing the distance from the point x0

[Walter Roberson]

Ah, but how do you define a "peak" for this purpose?

  A
 * *
*    *   C
*     **B **X**
*              *

Suppose C is within the defined range of X, but A is not within that range. C is a peak relative to BX, but C could also be said to only be on the shoulder of a different peak, A

[Vinay Killamsetty]

Hi, Walter.

I want to chek whether the Maximum peak of the plot is in the defined range.

Answer 1

[Walter Roberson]

Assuming you have a vector of x values (rather than x0 being an index), and that your signal is called y:

acceptable_idx = find(abs(x-x0)<=d);

[~, peakidx] = max(y);
if ismember(peakidx, acceptable_idx)
   %yes, peak is inside the desired interval
end

[Vinay Killamsetty]

Thank you very much.

This has solved my problem