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

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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?

Posted 23-Jan-14 23:27pm

Member 10512547

Updated 23-Jan-14 23:43pm

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Matt T Heffron · Answer 1 · 2014-01-24T07:32:00

Solution 1

I'm guessing the file is binary data so the importdata has created a cell array.
Try the cell2mat function[^] to convert to a matrix that fft can use.

Posted 24-Jan-14 7:32am

Matt T Heffron

Albert Holguin · Answer 2 · 2014-01-27T05:22:00

Solution 2

The fft()[^] routine functions on vectors and/or arrays (preferably on vectors of data type double, since we're talking about time a vector makes more sense). If your data is not in that format, then you have to get it in that format.

Posted 27-Jan-14 5:22am

Albert Holguin