How to find time at maximum amplitude in a signal

I have single variable(wave) x(time,volt). There are multiple wavelets (3 to 6) in the signal x. I want to find value of time (x axis) for maximum value of volt (y axis) in each wavelets. Goal is to find the difference in terms of time at positve peak of voltage - between wavelets in a single wave.

time (s) - voltage(v) 0 0 1 2 2 3 3 2 4 -2 5 -3 6 -2 7 0 8 2 9 5 10 7 11 3 12 -3 13 -6 14 -2 15 0 16 0 17 0 18 0 19 0 20 0 21 0 22 0 23 0 24 0 25 0 26 0 27 2 28 3 29 2 30 -2 31 -3 32 -2 33 0 34 2 35 5 36 10 37 3 38 -3 39 -6 40 -2

[Jan]

It is not getting clear to me. Please omit all unnecessary information like the physical meaning of the data - calculating the max of temperature or money is exactly the same in a program. Especially I do not get the dimension of your data array "variable(wave) x(time,volt)" - is it a vector?

Answer 1

[Paulo Silva]

maxvol=max(x(:,2))
timemaxvol=x((find(x(:,2)==maxvol)),1)

[Jan]

You can omit the FIND te use the faster logical indexing.

[Walter Roberson]

Paulo, the requirement is to find the maximum value for each of the 3 to 6 wavelets. If I recall correctly, wavelets are not confined to having a single peak, so even a peak-finding function would not be suitable here. I believe one would have to do a wavelet analysis using the same kind of wavelets that were used in the construction of the signal.