I have got a int16 array (called allAudio) and would like to run the function 'findpeaks' on it. When I write pks = findpeaks(allAudio(1,:)), the error message says: "Error using findpeaks (line 59) Input arguments must be 'double'."
I don't understand it... Any thoughts?
findpeaks only operates on numbers that are 64 bit floating point numbers (they're called doubles).
Convert your 16bit integers to double with the function "double".
double_allAudio = double(allAudio);
rng default x = randi(10, 1, 20, 'int8'); ILM = islocalmax(x); y = [x; ILM]
If you run those four commands, you'll see y is an int8 array and that most of the instances of 10 in x are local maxima, as is one of the instances of 9. To see that graphically:
% NaN values don't get plotted so preallocate then fill the local maxima z = NaN(size(x)); z(ILM) = x(ILM);
ind = 1:numel(x); plot(ind, x, '-', ind, z, 'ro');
The red circles correspond to the local maxima. The two plateaus each have one of their two points of equal height marked; see the documentation for islocalmax for more information about how you can customize how that behavior is handled.