ignal. The output are samples 
       of the instantaneous heart rate signal in units of beats per minute.

 Required Parameters:

 recorName
       String specifying the name of the record in the WFDB path or
       in the current directory.

 annotator  -
       String specifying the name of the annotation file in the WFDB path or
       in the current directory.

 Optional Parameters are:

 N 
       A 1x1 integer specifying the sample number at which to stop reading the 
       annotation file (default 