public float calc_Fox_Runge_Kutta(float f, float r, float ts)
{
foxws.foxws fproxy = new foxws.foxws();
float k1 = 0;
float k2 = 0;
float k3 = 0;
float k4 = 0;
k1 = fproxy.foxpop_inc(f, r); //f(y)
float tmp = f + (ts / 2) * k1;
k2 = fproxy.foxpop_inc((tmp), r); //f(y+(h/2)k1)
tmp = f + (ts / 2) * k2;
k3 = fproxy.foxpop_inc((tmp), r); //f(y+(h/2)k2)
tmp = f + ts * k3;
k4 = fproxy.foxpop_inc((tmp), r); //f(y+ hk3)
f = f + ts*(k1 + 2 * k2 + 2 * k3 + k4) / 6; //y + h*(k1 + 2 * k2 + 2 * k3 + k4)/6
return f;
}
protected double[,] hybrid_horizontal_same_ts(float r, float f, int yr, float ts, string r_integ_method, string f_integ_method)
{
//objective: the two models run with ts=0.1 but they exchange data at multiple of 1
foxws.foxws fproxy = new foxws.foxws();
rabws.rabws rproxy = new rabws.rabws();
//the system will loop according to the defined time step
//int lp = Convert.ToInt16(Math.Truncate(yr / ts)); //total number of loop due to the defined time step
int lp = Convert.ToInt32(Math.Truncate(yr / 0.1)); //10 timestep in 1 year
lp = lp + 2;
double[,] result = new double[lp, 2];
float rx = r;
float ry = f;
float fx = r;
float fy = f;
for (int i = 1; i < lp; i++)
{
if (i % (Convert.ToInt16(ts * 10)) == 0)
{
//run rabbit model
if (r_integ_method == "Runge-Kutta") // for Runge-Kutta integration of rabbit
{
r = calc_Rabbit_Runge_Kutta(r, f, ts);
}
else
rx = rx + rproxy.pop_inc(rx, ry) * ts; //for euler integration
//r = r + rabbit_model(r, f) * ts;
//run fox model
if (f_integ_method == "Runge-Kutta") // for Runge-Kutta integration of fox model
{
f = calc_Fox_Runge_Kutta(f, r, ts);
}
else
fy = fy + fproxy.foxpop_inc(fy, fx) * ts; //for euler integration
//f = f + fox_model(f, r) * ts;
if ((i % 10) == 0) //when ts is 1,2,3, ... then the models exchange data
{
ry = f;
fx = r;
}
r = rx;
f = fy;
if (r < 0)
result[i, 0] = 0;
else
result[i, 0] = r; //Convert.ToDouble(r.ToString("#.##"));
if (f < 0)
result[i, 1] = 0;
else
result[i, 1] = f; // Convert.ToDouble(f.ToString("#.##"));
if (result[i, 0] < 0) //(result[i, 0] < 1)
{
result[i, 0] = 0; //if pop<0 then set the pop value to 0
result[i, 1] = 0;
break;
}
}
else
{
if (r < 0) //(result[i, 0] < 1)
{
result[i, 0] = 0; //if pop<0 then set the pop value to 0
result[i, 1] = 0;
break;
}
else
{
result[i, 0] = r;
result[i, 1] = f;
}
}
}
return result;
}
