www.pudn.com > DFAandDataReplace.rar > dfa_exponent.m

function alpha1=dfa_exponent(sig) 
data=sig; 
data=dtrend(data); 
minbox=0;maxbox=0; 
nfit=2;%set nfit (the order of the regression fit) 
iflag=0;%input data are already integrated 
sw=1;%enable sliding window mode 
data=dtrend(data); 
seq=[1;cumsum(data)]; 
%seq=[1;data]; 
npts=length(seq)-1; 
% Set minimum and maximum box sizes 
if (minbox< 2*nfit) 
    minbox = 2*nfit; 
end 
if (maxbox == 0 || maxbox > npts/4)  
    maxbox = floor(npts/4); 
end 
if (minbox>maxbox)  
    temp = minbox; minbox = maxbox; maxbox = temp; 
    if (minbox < 2*nfit)  
        minbox = 2*nfit; 
    end 
end 
mex dfa_main.c 
alpha1=dfa_main(seq,minbox,maxbox,npts,nfit);