Function: instfreqplot
INSTFREQPLOT  Plot of instantaneous frequency
  Usage: instfreqplot(f,op1,op2, ... );
         instfreqplot(f,fs,op1,op2, ... );

  INSTFREQPLOT(f) plots the instantaneous frequency of f using a DGT.

  INSTFREQPLOT(f,fs) does the same for a signal with sampling rate
  fs Hz.

  The instantaneous frequency contains extreme spikes in regions
  where the spectrogram is close to zero. These points are usually
  uninteresting and destroy the visibility of the plot. Use the 'thr'
  or 'clim' or 'climsym' options (see below) to remove these points.

  An example:

    instfreqplot(greasy,16000,'thr',.03,'climsym',100);

  will produce a nice instantaneous frequency plot of the GREASY
  signal.

  INSTFREQPLOT accepts the following optional arguments:

    'tfr',v     Set the ratio of frequency resolution to time resolution.
                A value v=1 is the default. Setting v>1 will give better
                frequency resolution at the expense of a worse time
                resolution. A value of 0<v<1 will do the opposite.
 
    'wlen',s    Window length. Specifies the length of the window
                measured in samples. See help of PGAUSS on the exact
                details of the window length.
 
    'thr',r     Keep the coefficients with a magnitude larger than r*
                times the largest magnitude. Set the instantaneous 
                frequency of the rest of the coefficients to zero
 
    'nf'        Display negative frequencies, with the zero-frequency
                centered in the middle. For real signals, this will just
                mirror the upper half plane. This is standard for complex
                signals.
 
    'tc'        Time centering. Move the beginning of the signal to the
                middle of the plot. This is useful for visualizing the
                window functions of the toolbox.
 
    'image'     Use imagesc to display the spectrogram. This is the
                default.
 
    'dgt'       Use the 'dgt' method to compute the instantaneous
                frequency. This is the default.
 
    'clim',clim  Use a colormap ranging from clim(1) to clim(2). These
                 values are passed to imagesc. See the help on imagesc.
 
    'climsym',cval  Use a colormap ranging from -cval to cval
 
    'fmax',y    Display y as the highest frequency.

Url: http://ltfat.github.io/doc/gabor/instfreqplot.html

See also: sgram, resgram, phaseplot.

Package: ltfat