When you have numerical data, it is often convenient to find a simple formula that approximates it. For example, you can try to "fit" a line or curve through the points in your data.
One common way of picking out "signals" in numerical data is to find the Fourier transform
, or frequency spectrum, of the data.
Note that the Fourier
function in Mathematica
is defined with the sign convention typically used in the physical sciences—opposite to the one often used in electrical engineering. "Fourier Transforms"
gives more details.