How to do data selection from a graph to extract the evenly spaced data points ?

Dear peers, i would like to select or extract the data that the Y axis is more than 0.001. and then select 60 points that are evenly spaced out in the selected graph area.

for eg: The original graph is generated by matlab simulink. and would like to select the data that are in the Red rectangle.

the outcome is expected as follow: 30 data points that evenly space (closet) that are selected from each peaks.

What is the best search method to find the evenly space data points? and i would use this algorithm for different graphs.

Thank you very much

Answer 1

[KSSV]

Let X and Y be your data arrays.

N = 30 ;
xi = linspace(min(X),max(X),N) ;
yi = interp1(X,Y,xi) ;
plot(xi,yi)
axis([-100 100 0 0.04])

[Chin Kui Ku]

thanks, I supposed that need to extract the X & Y data arrays for those points of Y>0.001. for left quadrant, and right quadrants.

and the xi & yi mentioned above are regenerated by matlab correct? however, i am interested in selecting the existing closest x & y evenly spaced points. any idea on how to do so?

[KSSV]

iwant = [X(Y>0.001) Y(Y>0.001)] ;