protected override double Calculate(double a, double b, int n, string integral)
{
double res = 0;
double h = (b - a) / n;
for (int i = 1; i <= n; ++i)
{
res += MyParser.calculate(integral, (a + i * h));
}
res *= h;
return(res);
}
protected override double Calculate(double a, double b, int n, string integral)
{
double res = 0;
double h = (b - a) / n;
bool even = false;
for (int i = 1; i < n; ++i)
{
res += (even ? 2 : 4) * MyParser.calculate(integral, (a + i * h));
even = !even;
}
res += MyParser.calculate(integral, a) + MyParser.calculate(integral, b);
res *= h / 3;
return(res);
}
//public override KeyValuePair<double, int> CalculateIntegral(double a, double b, double eps, string integral)
//{
// int n = 3;
// double i1 = Calculate(a, b, n, integral);
// double i2 = 0;
// int k = 2;
// do
// {
// i2 = 0;
// for (int i = 0; i < k; i++)
// {
// i2 += Calculate(a + i * (b - a) / k, a + (i + 1) * (b - a) / k, n, integral);
// }
// double tmp = i2;
// i2 = i1;
// i1 = tmp;
// k++;
// } while (Math.Abs(i1 - i2) >= eps);
// return new KeyValuePair<double, int>(i1, k);
//}
protected override double Calculate(double a, double b, int n, string integral)
{
if (n == 8 || n > 9)
{
n = 9;
}
double res = 0;
double A = (b - a) / 2;
double B = (b + a) / 2;
double[] x = ChebyshevCoefs.arr[7].x;
for (int i = 0; i < ChebyshevCoefs.arr.Length; i++)
{
if (ChebyshevCoefs.arr[i].n == n)
{
x = ChebyshevCoefs.arr[i].x;
}
}
for (int i = 0; i < x.Length; i++)
{
res += MyParser.calculate(integral, A * x[i] + B);
}
return(2 * res * A / n);
}