function cdf = omega2cdf(x)
%
a1 =[]; j=0;

not_precise = 1;

while not_precise    
     add = gamma(j+1/2)/( gamma(1/2)*gamma(j+1)) * sqrt(4 * j +1) * ...
        (besseli(-0.25, (4 *j + 1)^2/(16*x),1) - besseli(0.25, (4 *j + 1)^2/(16*x),1 ));
        a1 = [a1 add];
        not_precise = (abs(add) > 10e-10);
        j=j+1;
end
cdf = 1/sqrt(2*x) * sum(a1);