CFD Online Discussion Forums - user defined functions

hi to everyone. i have a problem, i have to create an user defined function for an heat flow along z axis in a 3D geometry.the equation of the flow is a bell shape (see the image).the code that i wrote is :

Code:

DEFINE_PROFILE(flusso_radiativo, thread, position)

{

real x[ND_ND]; /* this will hold the position vector */

real z;

face_t f;

begin_f_loop(f, thread)

{

F_CENTROID(x,f,thread);

z = x[2];

F_PROFILE(f, thread, position) = 149529572.*1./(sqrt((2.*3.141593*(0.051*0.051))))*exp((-(z-0.2)*(z-0.2))/(2.*(0.051*0.051)));

}

end_f_loop(f, thread)

}

is it well written?thanks for help