function r = g_os( k_x, s_x, x)
%
% r = g_os( k_x, s_x, x)
%
% Gabbiani CAAM 415 11/25/08
%  
% This function returns the normalized response of an odd
% Gabor filter in space.
%
% k_x and s_x are the spatial frequency and the standard 
% deviation of the Gaussian in space
  
%make sure that we are in line format
x = x(:)';

%length of the spatial vector
n = length(x);

r = zeros(1,n);

C = 1/(sqrt(2*pi)*s_x);

r(1,1:n) = exp(-x.^2/(2*s_x^2)).*sin(k_x*x);

r = C*r;