Function: plotfft
PLOTFFT  Plot the output from FFT
  Usage: plotfft(coef);
         plotfft(coef,fs);

  PLOTFFT(coef) plots the output from the fft function. The
  frequency axis will use normalized frequencies between 0 and 1 (the
  Nyquist frequency).

  PLOTFFT(coef,fs) does the same for the FFT of a signal sampled at
  a sampling rate of fs Hz.

  PLOTFFT(coef,fs,dynrange) additionally limits the dynamic range of the
  plot. See the description of the 'dynrange' parameter below.

  PLOTFFT accepts the following optional arguments:

    'dynrange',r  Limit the dynamical range to r by using a colormap in
                  the interval [chigh-r,chigh], where chigh is the highest
                  value in the plot. The default value of [] means to not
                  limit the dynamical range. 

    'db'         Apply 20*log_{10} to the coefficients. This makes 
                 it possible to see very weak phenomena, but it might show 
                 too much noise. This is the default.

    'dbsq'       Apply 10*log_{10} to the coefficients. Same as the
                 'db' option, but assumes that the input is already squared.  

    'lin'        Show the coefficients on a linear scale. This will
                 display the raw input without any modifications. Only works for
                 real-valued input.
                
    'linsq'      Show the square of the coefficients on a linear scale.
                
    'linabs'     Show the absolute value of the coefficients on a linear
                 scale.

    'nf'         Display negative frequencies, with the zero-frequency
                 centered in the middle. This is the default.

    'posfreq'    Display only the positive frequencies.

    'dim',dim  If coef is multidimensional, dim indicates the 
               dimension along which are the individual channels oriented.
               Value 1 indicates columns, value 2 rows.

    'flog'     Use logarithmic scale for the frequency axis. This flag is
               only valid in conjuction with the 'posfreq' flag.


  In addition to these parameters, PLOTFFT accepts any of the flags
  from NORMALIZE. The coefficients will be normalized as specified
  before plotting.

Url: http://ltfat.github.io/doc/fourier/plotfft.html

See also: plotfftreal.

Package: ltfat