[Tufan Tuna]

I'm giving the rotational movement to circle boundary. Im getting syntax error at the F_PROFILE line about '='. I don't know why? Here is my code

#include <udf.h>
#include <math.h>
#define q = 5.0
				
DEFINE_PROFILE(inlet_x_velocity_on_cylinder, thread, position)
{
	
real x[ND_ND]; /* this will hold the position vector */
real y, xx;
real ang, r, u;
face_t f;


begin_f_loop(f,thread)
	{
	F_CENTROID(x, f, thread);
	xx = x[0];
	y = x[1]; 
	r = sqrt(pow(xx,2) + pow(y, 2));
	u = xx/r;

	F_PROFILE(f, thread, position)= sqrt(1.0 - pow(u,2)) + (sqrt(1.0 - pow(u,2)) / (2.0 * pow(r,3))) + ((3.0 / 2.0) * q * (1 / pow(r,4)) *(u * sqrt(1.0 - pow(u,2))) );
	}
end_f_loop(f, thread)
}

[Tufan Tuna]

Solved it. Macro definitions shouldn't contain equals sign.
at the line #define q = 5.0 sould be #define q 5.0