public override CSP Method(CSP csp0, double x1)
{
double h = x1 - csp0.x;
double y1 = csp0.y + h * f(csp0.x, csp0.y, csp0.z);
double z1 = csp0.z + h * g(csp0.x, csp0.y, csp0.z);
return(new CSP(x1, y1, z1));
}
static void Test_4_07(double x1)
{
SODE_4 RG_4 = new SODE_4(csp0, f_07, g_07);
CSP csp1 = RG_4.Solve_with_Precision(x1, eps);
err = Math.Abs(Sy1 - csp1.y) + Math.Abs(Sz1 - csp1.z);
SW.WriteLine($"\r\n Test - MAC_Sys_of_ODE_O1_RungeKutta_2:");
SW.WriteLine($" {csp1.x,8:F4}{csp1.y,14:F9}{Sy1,14:F9}"
+ $" {csp1.z,14:F9}{Sz1,14:F9}"
+ $"{err,11:E1} {RG_4.iter}");
}
public override CSP Method(CSP csp0, double x1)
{
double h = x1 - csp0.x;
double k1 = h * f(csp0.x, csp0.y, csp0.z);
double l1 = h * g(csp0.x, csp0.y, csp0.z);
double k2 = h * f(csp0.x + h, csp0.y + k1, csp0.z + l1);
double l2 = h * g(csp0.x + h, csp0.y + k1, csp0.z + l1);
double y1 = csp0.y + 0.5 * (k1 + k2);
double z1 = csp0.z + 0.5 * (l1 + l2);
return(new CSP(x1, y1, z1));
}
public override CSP Method(CSP csp0, double x1)
{
double h = x1 - csp0.x, h2 = 0.5 * h;
double k1 = h * f(csp0.x, csp0.y, csp0.z);
double l1 = h * g(csp0.x, csp0.y, csp0.z);
double k2 = h * f(csp0.x + h2, csp0.y + k1 * 0.5, csp0.z + l1 * 0.5);
double l2 = h * g(csp0.x + h2, csp0.y + k1 * 0.5, csp0.z + l1 * 0.5);
double k3 = h * f(csp0.x + h, csp0.y - k1 + 2 * k2, csp0.z - l1 + 2 * l2);
double l3 = h * g(csp0.x + h, csp0.y - k1 + 2 * k2, csp0.z - l1 + 2 * l2);
double y1 = csp0.y + (k1 + 4 * k2 + k3) / 6.0;
double z1 = csp0.z + (l1 + 4 * l2 + l3) / 6.0;
return(new CSP(x1, y1, z1));
}
static void Main(string[] args)
{
//csp0 = new CSP(0.0, 3.0, 5.0); x1 = 0.25;
//Sy1 = Sy_00(x1); Sz1 = Sz_00(x1);
//Test_1_00(x1); Test_2_00(x1);
//Test_3_00(x1);
//Test_4_00(x1);
csp0 = new CSP(0.0, 1.0, 3.0); x1 = 0.27;
Sy1 = Sy_07(x1); Sz1 = Sz_07(x1);
Test_1_07(x1); Test_2_07(x1);
Test_3_07(x1);
Test_4_07(x1);
SW.Close();
}
public MAC_Sys_of_ODE_Order_1_RungeKutta_2
(CSP csp, Func <double, double, double, double> f,
Func <double, double, double, double> g)
: base(csp, f, g)
{
}
abstract public CSP Method(CSP csp0, double x1);
public MAC_Sys_of_ODE_Order_1
(CSP csp, Func <double, double, double, double> f,
Func <double, double, double, double> g)
{
this.CSPO = new CSP(csp); this.g = g; this.f = f;
}
