NAME

       rtf_create_bandpass_analytic - Creates an IIR filter estimating the analytic signal in a bandpass.

SYNOPSIS

       #include <rtf_common.h>

       hfilter rtf_create_bandpass_analytic(unsigned int nch, int proctype,
                                            double fl, double fh,
                                            unsigned int num_pole);

DESCRIPTION

       rtf_create_chebychev()  creates  a IIR chebychev filter processing nch channels of data type specified by
       proctype. The output of the filter is the analytic signal of the bandpassed data between  the  normalized
       frequencies  fl and fh. The num_pole parameter specifies the number of poles of the Chebychev filter used
       as the basis of the analytic filter.

       A normalized frequency is the ratio between the absolute frequency and the  sampling  frequency  (i.e.  a
       value of 1.0 refers to the sampling frequency).

       The  Z-transform of this filter has complex coefficients. So like rtf_create_filter(3) the created filter
       will output complex values keeping the precision specified by proctype.

       It is important to note that this filter can quickly become unstable as  the  number  of  pole  specified
       increased.  Please  refers to the authors of the library to know the stability domain (TODO: provides the
       stability domain here)

RETURN VALUE

       Returns the handle to the created filter in case of success, NULL otherwise.

SEE ALSO

       rtf_create_filter(3), rtf_destroy_filter(3)