Christos Saragiotis

John,

thank you very much for your comments and the time you spent on thoroughly checking this function.

I will try to incorporate your suggestions, when I find some time

Dear William,

1. Regarding the "slowness issue":

This function is in fact FASTER than the submissions by Telasula and Barrows (btw Barrowes' submission is not something you can run, unless you correct it).

For example for an input of 200,000 samples, in my machine I get:
Barrows: 5.5 sec, Telasula: 3.1 sec, this function: 1.8 sec

This function is indeed slower than Barrowes' and Talasula's ones when you have inputs with very few samples (say 20 samples or so) but in that case the time of execution is of the order of msec. I think that 3 msec vs. 0.3 msec is not a waste of anyone's time.

2. Regarding the "accuracy issue":

Abramowitz's and Stegun's tables are accurate to the 10th decimal. Interpolation for other values was not my idea it was Abramowitz's and Stegun's idea. The accuracy of the interpolation was commented in the description of the file above. I don't see how your "findings" on the accuracy contribute anything new. By the way, what is the accuracy of Barrowes' or Telasula's submissions?

In my opinion it is very unfortunate that you gave a bad rating based
- on something which doesn't hold ("slowness") and
- on a limitation ("accuracy") which is however stated in both the description and the help of the function.

Very good and an excellent example of terse programming.

I have two remarks though:
1. when selecting the 'both' option some peaks or troughs may be lost. E.g consider the vector [0, 5 -5, 5, 0]. Clearly -5 is a trough but localpeaks will not pick it.
2. if we consider again the vector [ 0 5 5 5 0], localpeaks will pick the first and last 5 as a peak but not the second one. I'm not sure if this was intentional but the way I see it it should either pick all of them or none.

nice