Function: firfilter
FIRFILTER  Construct an FIR filter
  Usage:  g=firfilter(name,M);
          g=firfilter(name,M,...);

  FIRFILTER(name,M) creates an FIR filter of length M. This is
  exactly the same as calling FIRWIN. The name must be one of the
  accepted window types of FIRWIN.

  FIRFILTER(name,M,fc) constructs a filter with a centre
  frequency of fc measured in normalized frequencies.

  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.

  FIRFILTER accepts the following optional parameters:

    'fs',fs     If the sampling frequency fs is specified then the length
                M is specified in seconds and the centre frequency
                fc in Hz.

    '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.

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

    'causal'    Create a causal filter starting at the first sample. If
                specified, this flag overwrites the delay setting.

  It is possible to normalize the impulse response 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.

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

See also: blfilter, firwin, pfilt, filterbank.

Package: ltfat