.. highlightlang:: us

.. index:: fft

.. _fft:

fft
===

.. us.tag  fft ENGLISH fft

The *fft* function computes the complex Fourier Transformation.

.. function::  cvFFT = fft(cv)

.. us.return

**Return Value**

*cvFFT* is the result of the Fourier Transformation of *cv*.

.. us.params

**Parameters**

.. uparam:: cv

   *cv* is a real or complex vector.

.. us.comment

**Comment**

If *cv* is a matrix, all columns will be transformed parallelly.

.. us.example

**Example**

::

   def Spectrum(signal, rsAbtastfrequenz)
   {
       S = fft(signal);
       nS = len(S)/2;
       w = (0:(nS-1))/nS * rsAbtastfrequenz/2;
       return [w', abs(S[1:nS])'];
   }

   Fs = 100;
   t = (1:100)/Fs;
   s1 = sin(2*PI*t * 5);
   s2 = sin(2*PI*t * 15);
   s3 = sin(2*PI*t * 30);
   s = s1+s2+s3;
   plot(t,s);
   rmXY = Spectrum(s, Fs);
   plot(rmXY[;1], rmXY[;2]);

.. image:: S:/uniplot-obj/images/fft.*

.. seealso::
   :ref:`overview-mathematic`,
   :ref:`ifft`

:sub:`id-2041055`