public double Count(MethodContext context)
{
int n = 6;
double[] a = new double[n + 1];
double[] y = new double[n];
double[] z = new double[n];
double[] w = new double[n];
double res = 0;
double[] u = new double[n];
int N = 0;
if (n % 2 == 0)
{
N = n / 2;
}
else
{
N = (n - 1) / 2;
}
// calculate coefficients of Legendre polynomial
for (int i = 0; i <= N; i++)
{
a[n - 2 * i] = (Math.Pow(-1, i) * fact(2 * n - 2 * i)) / (Math.Pow(2, n) * fact(i) * fact(n - i) * fact(n - 2 * i));
}
// calculate coefficients
for (int i = 0; i < n; i++)
{
double _a = 3.14 * (i + 0.75) / (n + 0.5);
double _b = 3.14 * (i / n);
z[i] = Math.Cos(3.14 * (i + 0.75) / (n + 0.5));
y[i] = z[i];
w[i] = 2 / ((1 - Math.Pow(z[i], 2)) * (derP_n(a, n, n % 2, z[i]) * derP_n(a, n, n % 2, z[i])));
}
// broaden abcisses from [-1,1] to [A,B]
for (int i = 0; i < n; i++)
{
u[i] = ((context.B - context.A) * y[i] / 2) + (context.B + context.A) / 2;
}
for (int i = 0; i < n; i++)
{
res += w[i] * context.Function.Evaluate(u[i]);
}
res *= (context.B - context.A) / 2;
return(res);
}
public double Count(MethodContext context)
{
double h = (context.B - context.A) / context.N;
double toReturn = 0;
for (int i = 0; i < context.N; ++i)
{
double start = context.A + i * h;
double end = context.A + (i + 1) * h;
toReturn += h * context.Function.Evaluate((start + end) / 2);
}
return(toReturn);
}
public double Count(MethodContext context)
{
double h = (context.B - context.A) / context.N;
double toReturn = context.Function.Evaluate(context.A);
for (int i = 1; i < context.N; ++i)
{
toReturn += 2 * context.Function.Evaluate(context.A + i * h);
}
toReturn += context.Function.Evaluate(context.B);
toReturn *= (context.B - context.A) / (2 * context.N);
return(toReturn);
}
public double Count(MethodContext context)
{
double M = context.N / 2;
double h = (context.B - context.A) / (2 * M);
double res = context.Function.Evaluate(context.A);
for (int i = 1; i <= M; ++i)
{
res += 2 * context.Function.Evaluate(context.A + h * (2 * i - 1));
res += 4 * context.Function.Evaluate(context.A + h * 2 * i);
}
res += context.Function.Evaluate(context.B);
res *= (context.B - context.A) / (6 * M);
return(res);
}
