function [a b g] = filon_coeffs(th)
if(th>.1)
a = 1./th+sin(2*th)./(2*th.^2)-2*sin(th).^2./(th.^3);
else
a = (2*th.^3)/45-(2*th.^5)/315+(2*th.^7)./4725;
end

if(th>.1)
  b = 2*((1+cos(th).^2)./(th.^2)-sin(2*th)./(th.^3));
else
  b = 2/3+2*th.^2/15-4*th.^4/105+2*th.^6/567;
end

if(th>.1)
g = 4*(sin(th)./th.^3-cos(th)./th.^2);
else
g = 4/3-2*th.^2/15+th.^4/210-2*th.^6/11340;
end



