/**********************************************************************
   UDF to calculate standard deviation and mean of the Monroe Parameter.             
***********************************************************************/
#include "udf.h"

DEFINE_ON_DEMAND(on_demand2_calc)
{
   Domain *d;

   real velocity;
   Thread *t;
   cell_t c;
   Node *nod;
   int n;
   int density=1000;
   double visc=1e-6;
   double temp;
   double pos_x;
   double pos_y;
   double xvel;
   double yvel;
   double xprev=0;
   double yprev=0;
   double MeshArea=0;
   double cell_area=0;
   double magvel=0;
   double flowtot=0;
   double Monroe_sum = 0;
   double Monroe = 0;
   double theta = 0;
   double stdev = 0;

   d = Get_Domain(1);     /* Get the domain using Fluent utility */

   /* Loop over all cell threads in the domain */
   thread_loop_c(t,d)
     {
     printf("\n Sum of All Flows = %g\n", flowtot);
     /* Loop over all cells  */
     begin_c_loop(c,t)
       {
		    double delta_x = 0;
			double delta_y = 0;
			int run_number = 0;
		    for (n=0; n < cell_type_nnodes[(int)C_TYPE(c,t)]; n++) 	 
				{
					nod = C_NODE(c, t, n); 
					pos_x=NODE_X(nod);
					pos_y=NODE_Y(nod);
					
				if(run_number>0)
				{
					if(delta_x<fabs(pos_x-xprev))
						delta_x= fabs(pos_x-xprev);
					
					if(delta_y < fabs(pos_y-yprev))
						delta_y = fabs(pos_y-yprev);
					
				}
				run_number = run_number +1;
				xprev = pos_x;
				yprev = pos_y;

				}
			
		Monroe = sqrt(C_D(c,t))*delta_x*delta_y;
		Monroe_sum = Monroe_sum + Monroe;
       }
     		end_c_loop(c,t)	
		printf("G_pheta = %g\n", (Monroe_sum/.01/sqrt(visc)));
	}
}