二维插值方法.rar

#include "interpolation.h" Interpolation::Interpolation() { } double Interpolation::Lagrange(int N, vector<double>& X, vector<double>& Y, double x) { double result = 0; for (int i = 0; i < N; i++) { double temp = Y[i]; for (int j = 0; j < N; j++) { if (i != j) { temp = temp * (x - X[j]); temp = temp / (X[i] - X[j]); } } result += temp; } return result; } double Interpolation::ChaShang(int n, vector<double>& X, vector<double>& Y) { double f = 0; double temp = 0; for (int i = 0; i < n + 1; i++) { temp = Y[i]; for (int j = 0; j < n + 1; j++) if (i != j) temp /= (X[i] - X[j]); f += temp; } return f; } double Interpolation::Newton(double x, vector<double>& X, vector<double>& Y) { double result = 0; for (unsigned int i = 0; i < X.size(); i++) { double temp = 1; double f = ChaShang(i, X, Y); for (unsigned int j = 0; j < i; j++) { temp = temp * (x - X[j]); } result += f * temp; } return result; }