Strange error message using sort( ) ?

Hey

I am trying to locate the 10 fundamental frequencies in my power-spectrum. I know, I can find the peaks, by using the findpeaks() function. Then, I would like to sort these peaks and index them. I thought the following code would do this, but I get an error message I don't understand?

>> Y=abs(fft(channel1)); >> nyquist=ceil(length(Y)/2); >> peaks=findpeaks(Y(1:nyquist)); >> [A,I]=sort(peaks) Indexing cannot yield multiple results.

Answer 1

[Stephen23]

You have defined a variable called sort, and this is shadowing (i.e. hiding) the inbuilt sort function. MATLAB uses your sort variable and tries to index into it using the variable peaks, but it gets confused by the multiple outputs that you request.

The solution: do not use inbuilt function names for naming variables or functions. You can clear your workspace to remove the variables, and in future use which to check if a name is already used.