   function [count] = sturm(d, b, sigma)
%% function [count] = sturm(d, b, sigma)
%% Set b(1) = 0;
   b(1) = 0;
   n = length(d);
   count = 0;
   t = 1.0;
   for k=1:n
     t = d(k)-sigma - b(k)^2/t;
     %%%if (t == 0), t=1.0;,end
     if (t>=0), count=count+1; , end
   end
   
     
