I have the following code which runs but doesn't do what I want it to do. Here am reading data from a file and I want to group it according to its DUR,e.g. the event that have a DUR=1 be in the subfolder 01 under events, and so forth.

   fn=sprintf('ridging_daily_evolution_1980.txt');
   A=load(fn);

   [m,n]=size(A);
   for i=1:m-1
            DUR=A(i,5);
            lat=A(i,3);
            lon=A(i,2);
           if DUR ~=1
            DATE=A(i-(DUR-1),1);
           else
                DATE=A(i,1);
           end

             STR_DUR=num2str(DUR);
             STR_DATE = num2str(DATE);
             B = [STR_DATE lon lat STR_DUR];
            if DUR < 10 && DUR >0
                DUR_NAME = sprintf('0%s',STR_DUR);
            else
                DUR_NAME = sprintf(STR_DUR);
            end
   end
            gn=sprintf('events/%s/%s',DUR_NAME,STR_DATE);
            fid = fopen(gn,'wt');
            fprintf(fid,'%10.2f   %10.2f  %10.2f   %10.2f\n',B');
            fclose(fid);