static double Fe(double e, double r, bool waveFun = false)
{
double rmin = 1e-3;
if (r < rmin)
{
return(r - r * r);
}
Func <double, vector, vector> s = delegate(double x, vector y) {
return(new vector(y[1], 2 * (-1 / x - e) * y[0]));
};
vector ymin = new vector(rmin - rmin * rmin, 1 - 2 * rmin);
rk swave = new rk(s, rmin, r, ymin, initStep: 0.001, storeVal: waveFun); //my own 32 stepper
if (waveFun)
{
List <double> rs = rk.ts;
List <vector> fs = rk.ys;
var data = new StreamWriter("data.txt");
for (int i = 0; i < rs.Count; i++)
{
data.Write($"{rs[i]} {fs[i][0]} {rs[i]*Exp(-rs[i])}\n");
}
data.Close();
}
return(swave.yb[0]);
}
static void Main()
{
Func <double, vector, vector> f = delegate(double x, vector y) {
return(new vector(y[1], -y[0]));
};
rk sincos = new rk(f, 0, 2 * PI, new vector(0, 1), storeVal: true);
/* Write($"sin(1) = {sincos.yb[0]}\n");
* Write($"cos(1) = {sincos.yb[1]}\n"); */
List <double> ts = rk.ts; // list to store intermediate t values
List <vector> ys = rk.ys; // list to store intermediate f(t) valyes
for (int i = 0; i < ts.Count; i++)
{
Write("{0:f10} {1:f15} {2:f15}\n", ts[i], ys[i][0], ys[i][1]);
}
}
public Irk Create(
ImmutableList <IrkCrossJoinElement> value)
{
Irk crossJoin = null;
try
{
crossJoin = new rk(
value);
}
catch (Exception exception)
{
this.Log.Error(
exception.Message,
exception);
}
return(crossJoin);
}
static void Main()
{
double N = 550; //population in ten thousands
double Tr = 15; //recovery time in days
double Tc = 0.01; //time between contacts in days
Func <double, vector, vector> f = delegate(double x, vector y) {
double n = y[0] + y[1] + y[2];
return(new vector(-y[1] * y[0] / (n * N * Tc), y[1] * y[0] / (n * N * Tc) - y[1] / Tr, y[1] / Tr));
};
rk sir = new rk(f, 0, 150, new vector(550, 1, 0), storeVal: true);
/* Write($"sin(1) = {sincos.yb[0]}\n");
* Write($"cos(1) = {sincos.yb[1]}\n"); */
List <double> ts = rk.ts; // list to store intermediate t values
List <vector> ys = rk.ys; // list to store intermediate f(t) valyes
for (int i = 0; i < ts.Count; i++)
{
Write("{0:f10} {1:f15} {2:f15} {3:f15}\n", ts[i], ys[i][0], ys[i][1], ys[i][2]);
}
}
