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dfa

    function [ln,lf]=dfa(varargin)

     [ln,lf]=dfa(x,p,integrateFlag,minBoxSize,maxBoxSize,slideWindowFlag)

     Wrapper to the DFA Algorithm in:
        http://www.physionet.org/physiotools/dfa/

     References:
     Peng C-K, Buldyrev SV, Havlin S, Simons M, Stanley HE, Goldberger AL. Mosaic organization of DNA nucleotides. Phys Rev E 1994;49:1685-1689.
     Peng C-K, Havlin S, Stanley HE, Goldberger AL. Quantification of scaling exponents and crossover phenomena in nonstationary heartbeat time series. Chaos 1995;5:82-87.

     Please cite at least one of the above publications when referencing this
     material.

     Required Input Options are:

     x
           A Nx1 vector of doubles.

     Optional Input Options are:

     p
           Detrend using a polynomial of degree p (default: p=1, linear
           detrending).

     integrateFlag
           Input series is already integrated ( default= false ).

     minBoxSize
           Smallest box width (default: 2p+2)

     maxBoxSize
           Largest box width (default: N/4)

     slideWindowFlag
           Sliding window DFA (default =false);

     The Output variables are:

     ln
           A (MaxBoxSize -MinBoxSize) x 1 vector of log(boxsize)

     lf
           A (MaxBoxSize -MinBoxSize) x 1 vector of the log of the root
           mean square fluctuation for the given boxsize.

     Written by Ikaro Silva, 2014
     Last Modified: November 21, 2014
     Version 1.0

     Since 0.9.8

     %Example:

      gqrs('mitdb/117');
      [rr]=ann2rr('mitdb/117','qrs');
      [ln,lf]=dfa(rr);
      plot(ln,lf)

     See also MSENTROPY, SURROGATE