Function: warpedblfilter
WARPEDBLFILTER  Construct a warped band-limited filter
  Usage:  g=warpedblfilter(winname,fsupp,fc,fs,freqtoscale,scaletofreq);

  Input parameters:
     winname     : Name of prototype.
     fsupp       : Support length of the prototype (in scale units).
     fc          : Centre frequency (in Hz).
     fs          : Sampling rate
     freqtoscale : Function handle to convert Hz to scale units
     scaletofreq : Function to convert scale units into Hz.

  Output parameters:
     g           : Filter definition, see BLFILTER.

  WARPEDBLFILTER(winname,fsupp,fc,fs,freqtoscale,scaletofreq) constructs
  a band-limited filter that is warped on a given frequency scale. The 
  parameter winname specifies the basic shape of the frequency response.
  The name must be one of the shapes accepted by FIRWIN. The support of
  the frequency response measured on the selected frequency scale is 
  specified by fsupp, the centre frequency by fc and the scale by the
  function handle freqtoscale of a function that converts Hz into the 
  choosen scale and scaletofreq doing the inverse.

  If one of the inputs is a vector, the output will be a cell array
  with one entry in the cell array for each element in the vector. If
  more input are vectors, they must have the same size and shape and the
  the filters will be generated by stepping through the vectors. This
  is a quick way to create filters for FILTERBANK and UFILTERBANK.

  WARPEDBLFILTER accepts the following optional parameters:

    'complex'      Make the filter complex valued if the centre frequency
                   is non-zero. This is the default.

    'real'         Make the filter real-valued if the centre frequency
                   is non-zero.

    'symmetric'    The filters with fc<0 (or fc>fs/2) will be created
                   on the positive frequencies and mirrored. This allows
                   using freqtoscale defined only for the positive 
                   numbers.

    'delay',d      Set the delay of the filter. Default value is zero.

    'scal',s       Scale the filter by the constant s. This can be
                   useful to equalize channels in a filterbank.

  It is possible to normalize the transfer function of the filter by
  passing any of the flags from the NORMALIZE function. The default
  normalization is 'energy'.

  The filter can be used in the PFILT routine to filter a signal, or
  in can be placed in a cell-array for use with FILTERBANK or
  UFILTERBANK.

  The output format is the same as that of BLFILTER. 

Url: http://ltfat.github.io/doc/sigproc/warpedblfilter.html

See also: blfilter, firwin, pfilt, filterbank.

Package: ltfat