public static double Integrate(Func <double, double> func,
double a, double b, double alpha, double beta, int n)
{
var Mu = Mathematics.GetMuArray(n, a, b, alpha, beta);
double[] X = new double[n];
double h = (b - a) / (n - 1);
for (int i = 0; i < n; i++)
{
X[i] = a + h * i;
}
double[,] matrix = new double[n, n];
for (int i = 0; i < n; i++)
{
for (int j = 0; j < n; j++)
{
matrix[i, j] = Math.Pow(X[j], i);
}
}
var A = Mathematics.GausMethod(matrix, Mu);
double integralSum = 0;
for (int i = 0; i < n; i++)
{
integralSum += func(X[i]) * A[i];
}
return(integralSum);
}
public static double Integrate(Func <double, double> func,
double a, double b, double alpha, double beta, int n)
{
var Mu = Mathematics.GetMuArray(2 * n, a, b, alpha, beta);
var SLAE = new double[n, n];
var bSLAE = new double[n];
for (int i = 0; i < n; i++)
{
for (int j = 0; j < n; j++)
{
SLAE[i, j] = Mu[j + i];
}
bSLAE[i] = -Mu[n + i];
}
var acoefs = Mathematics.GausMethod(SLAE, bSLAE);
var polcoefs = new double[acoefs.Length + 1];
for (int i = 0; i < polcoefs.Length - 1; i++)
{
polcoefs[i] = acoefs[i];
}
polcoefs[polcoefs.Length - 1] = 1;
var nodes = GetSquarePolynomialRoots(polcoefs);
for (int i = 0; i < n; i++)
{
for (int j = 0; j < n; j++)
{
SLAE[i, j] = Math.Pow(nodes[j], i);
}
bSLAE[i] = Mu[i];
}
var intcoefs = Mathematics.GausMethod(SLAE, bSLAE);
double result = 0;
for (int i = 0; i < n; i++)
{
result += intcoefs[i] * func(nodes[i]);
}
return(result);
}