private List <string> getResults(IDerivativeFunction function, double eps, double x1, double x2, double alpha, double betta, double lambda)
{
List <string> results = new List <string>();
double x1_prev, x2_prev;
double dx1, dx2;
double prevFunc, resFunc;
int k = 1;
do
{
dx1 = function.getDerivativeX1().getY(x1, x2); //первая производная по х1
dx2 = function.getDerivativeX2().getY(x1, x2); //первая производная по x2
x1_prev = x1;
x2_prev = x2;
x1 -= alpha * dx1; //новое х1
x2 -= alpha * dx2; //новое х2
prevFunc = function.getY(x1_prev, x2_prev);
resFunc = function.getY(x1, x2);
results.Add(String.Format("k={0} x1={1} x2={2} f(x1,x2)={3}", k++, Math.Round(x1, 3), Math.Round(x2, 3), Math.Round(resFunc, 3)));
if (resFunc > prevFunc - 0.5 * lambda * Math.Sqrt(Math.Pow(dx1, 2) + Math.Pow(dx2, 2)))
{
alpha = lambda * betta;
}
} while ((Math.Abs(resFunc - prevFunc) > eps));
return(results);
}
public List <string> getResults(IDerivativeFunction function, double x1, double x2, double e, double lam)
{
List <string> results = new List <string>();
int i = 0;
// TO-DO remove code duplication
Matrix grad = calculateGrad(function, x1, x2);
x1 -= x1 - e * grad.get(0, 0);
x2 -= x2 - e * grad.get(0, 1);
results.Add(String.Format("k={0} x1={1} x2={2} f(x1,x2)={3}", i++, Math.Round(x1, 3), Math.Round(x2, 3), Math.Round(function.getY(x1, x2), 3)));
Matrix prevGrad;
do
{
prevGrad = grad;
grad = calculateGrad(function, x1, x2);
x1 -= lam * grad.get(0, 0);
x2 -= lam * grad.get(0, 1);
results.Add(String.Format("k={0} x1={1} x2={2} f(x1,x2)={3}", i++, Math.Round(x1, 3), Math.Round(x2, 3), Math.Round(function.getY(x1, x2), 3)));
} while (Math.Abs((prevGrad - grad).get(0, 0)) > e && Math.Abs((prevGrad - grad).get(0, 1)) > e);
return(results);
}
private Matrix calculateGrad(IDerivativeFunction function, double x1, double x2)
{
return(new Matrix(new double[1, 2] {
{ function.getDerivativeX1().getY(x1, x2), function.getDerivativeX2().getY(x1, x2) }
}));
}
