function varargout=wabp(varargin)

 wabp(recName,beginTime,stopTime,resample,signal)

    Wrapper to WFDB WABP:
         http://www.physionet.org/physiotools/wag/wabp-1.htm

 Attempts to locate arterial blood pressure (ABP) pulse waveforms in a continuous ABP signal
 in the specified WFDB record "recName". The detector algorithm is based on analysis of the first derivative
 of the ABP waveform. The output of WABP is an annotation file (with annotator name WABP) in which all
 detected beats are labelled normal.

 WABP can process records containing any number of signals, but it uses only one signal for ABP pulse
 detection (by default, the lowest-numbered ABP, ART, or BP signal; this can be changed using the
 'signal' option, see below). WABP is optimized for use with adult human ABPs.
 It has been designed and tested to work best on signals sampled at 125 Hz. For other ABPs, it may be
 necessary to experiment with the sampling frequency as recorded in the input record’s header file
 (see WFDBDESC ).



 CITING CREDIT: To credit this function, please cite the following paper at your work:

 Zong, W., Heldt, T., Moody, G. B., & Mark, R. G. (2003).
 An open-source algorithm to detect onset of arterial blood pressure pulses.
 Computers in Cardiology 2003, 30, 259-262. IEEE.


Required Parameters:

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


 Optional Parameters are:

 beginTime (Optional)
       String or integer specifying the begin time. The
       WFDB time format is described at
       http://www.physionet.org/physiotools/wag/intro.htm#time.
       If an integer is entered, it  should be between 1
       (first sample) and N (last sample).

 stopTime (Optional)
       String or integer specifying the begin time. If string, it should be
       in WFDB time format, if it is an integer, should be between 1
       (first sample) and N (last sample).

 resample
       A 1x1 boolean. If true resamples the signal to 125 Hz (default=0).

 signal
       A 1x1 integer. Specify the signal index of the WFDB record to be
       used for ABP pulse detection.


 C Source file written by Wei Zong 1998
 C Source file revised by George Moody 2010

 MATLAB Wrapper Written by Ikaro Silva, 2013
 Last Modified: January 16, 2013
 Version 1.1

 Since 0.9.0

 See also RDANN, RDSAMP, WFDBDESC, WFDBTIME


 %Example - Note this will create the file: ./slpdb/slp60.wabp in you
 %directory
 N=2000;
 [signal,Fs,tm]=rdsamp('slpdb/slp60',2,N);
 [endTime,dateStamp]=wfdbtime('slpdb/slp60',N);
 wabp('slpdb/slp60',[],endTime{1},[],2);
 [ann]=rdann('slpdb/slp60','wabp')
 plot(tm,x);hold on;grid on
 plot(tm(ann),x(ann),'or')