Using For Loop in a function over all files in a folder with Matlab

Dear Matlab Users,

I want to use for loop in a function over all files in a folder.

I want to apply the genhurst function over all files in a folder.

H = genhurst(S) 

where S is the time series with 1*6154 vector.

Here, I am explaining the details of the genhurst function as follows.

function [mH,sH]=genhurst(S,q,maxT)
if nargin < 2, q = 1; maxT = 19; end
if nargin < 3,  maxT = 19; end
if size(S,1)==1 & size(S,2)>1
    S = S';
elseif size(S,1)>1 & size(S,2)>1
    fprintf('S must be 1xT  \n')
    return
end
if size(S,1) < (maxT*4 | 60)
    warning('Data serie very short!')
end
L=length(S);
lq = length(q);
H  = [];
k = 0;
for Tmax=5:maxT
    k = k+1;
    x = 1:Tmax;
    mcord = zeros(Tmax,lq);
 	for tt = 1:Tmax
        dV = S((tt+1):tt:L) - S(((tt+1):tt:L)-tt);
        VV = S(((tt+1):tt:(L+tt))-tt)';
        N = length(dV)+1;
        X = 1:N;
        Y = VV;
        mx = sum(X)/N;
        SSxx = sum(X.^2) - N*mx^2;
        my   = sum(Y)/N;
        SSxy = sum(X.*Y) - N*mx*my;
        cc(1) = SSxy/SSxx;
        cc(2) = my - cc(1)*mx;
        ddVd  = dV - cc(1);
        VVVd  = VV - cc(1).*(1:N) - cc(2);
         %figure
         %plot(X,Y,'o')
         %hold on
         %plot(X,cc(1)*X+cc(2),'-r')
         %figure
         %plot(1:N-1,dV,'ob')
         %hold on
         %plot([1 N-1],mean(dV)*[1 1],'-b')
         %plot(1:N-1,ddVd,'xr')
         %plot([1 N-1],mean(ddVd)*[1 1],'-r')
        for qq=1:lq
            mcord(tt,qq)=mean(abs(ddVd).^q(qq))/mean(abs(VVVd).^q(qq));
        end
    end
    mx = mean(log10(x));
    SSxx = sum(log10(x).^2) - Tmax*mx^2;
    for qq=1:lq
        my = mean(log10(mcord(:,qq)));
        SSxy = sum(log10(x).*log10(mcord(:,qq))') - Tmax*mx*my;
        H(k,qq) = SSxy/SSxx;
    end
end
%figure
%loglog(x,mcord,'x-')
mH = mean(H)'./q(:);
if nargout == 2
    sH = std(H)'./q(:);
elseif nargout == 1
    sH = [];
end

In a folder, I have 20 Excel files having 2 columns in each file.

The first column represents the date whereas the 2nd column represents the time series.

Further, I want to calculate the monthly average of the estimated values for each time series.

Please help me to loop this function, and take the monthly average of the estimated values over all the files in a folder.

Thank you.

[KALYAN ACHARJYA]

Have you called files one by one and do operation?

[RP]

Yes, I called files in the following way.

thepath='F:\SP\Data';

xlfiles=dir(fullfile(thepath,'*.xlsx'));

nfiles=length(xlfiles);

Is it correct?

Thank you very much.

[Image Analyst]

What did you pass in for S,q,maxT? Whic variable is the "estimated" values?

[RP]

S is the column vector, and q and maxT are defined in the function. I want to calculate genhurst for the multiple column vectors on a monthly basis.

Here, I arranged each vector in separate excel files, and attached folder path in the code. However, one can arrange all the column vectors in 1 excel file, and calculate the function by looping across the columns. I tried this way also but unable to that.

Please help in this regards.

Thank you.