How Do I Use Fft Function In Matlab To Find The Frequency For A Set Of Data Points?

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Fam 2014-1-24

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评论： Iain 2014-1-29

 hi ive been given a set of about 20k data points. i managed to import the data into matlab and did the following,

importdata; fft(importdata);

and it says Undefined function 'fft' for input arguments of type 'cell'. now i understand i need more than this to get it working, can someone please tell me any more parameters i need for the fft and how to implement it?

edit: these datapoints are timestamps of when something is detected in a machine, im trying to find if there is a period of the detection occuring.

anyone have ideas how to trasnform it so i can use matlab fft? Imp

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Iain 2014-1-24

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If what you have is the times of occurrences, then a fft is inappropriate. - FFTs require regularly sampled data.

I don't know what your "importdata" looks like. You'll need to provide a description.

If what your data looks like is something like a table of

 timestamp: event
 timestamp: event

Then you can simply calculate the difference between each time stamp. If you then plot the difference in timestamp, you'll probably see several clusters of values. Each cluster is likely to be the period of a regular event - or a multiple of it.