static void Multiple_Roots(Expression f, float x0, float tol, int ite)
{
var xdict = new Dictionary <string, FloatingPoint> {
{ "x", x0 }
};
Expression x = Expression.Symbol("x");
Expression df = Calculus.Differentiate(x, f);
Expression d2f = Calculus.Differentiate(x, df);
int cont = 0;
float absError = tol + 1;
float relError;
float x1;
float fx = (float)Evaluate.Evaluate(xdict, f).RealValue;
float dfx = (float)Evaluate.Evaluate(xdict, df).RealValue;
float d2fx = (float)Evaluate.Evaluate(xdict, d2f).RealValue;
float denominator = (float)Math.Pow(dfx, 2) - (fx * d2fx);
Console.WriteLine("|{0,-4}|{1,-15}|{2,-15}|{3,-15}|{4,-15}|{5,-15}|{6,-15}|", "cont", "x", "fx", "dfx", "d2fx", "AbsError", "RelError");
Console.WriteLine("|{0,-4}|{1,-15}|{2,-15}|{3,-15}|{4,-15}|{5,-15}|{6,-15}|", cont, x0, fx, dfx, d2fx, "", "");
while (fx != 0 && absError > tol && denominator != 0 && cont < ite)
{
x1 = x0 - ((fx * dfx) / denominator);
xdict["x"] = x1;
fx = (float)Evaluate.Evaluate(xdict, f).RealValue;
dfx = (float)Evaluate.Evaluate(xdict, df).RealValue;
d2fx = (float)Evaluate.Evaluate(xdict, d2f).RealValue;
denominator = (float)Math.Pow(dfx, 2) - (fx * d2fx);
absError = Math.Abs(x1 - x0);
relError = absError / Math.Abs(x1);
x0 = x1;
cont++;
Console.WriteLine("|{0,-4}|{1,-15}|{2,-15}|{3,-15}|{4,-15}|{5,-15}|{6,-15}|", cont, x0, fx, dfx, d2fx, absError, relError);
}
if (fx == 0)
{
Console.WriteLine("\n" + x0 + " is a root.");
}
else if (absError < tol)
{
Console.WriteLine("\n" + x0 + " approximates to the function's root with a tolerance of: " + tol.ToString());
}
else if (denominator == 0)
{
Console.WriteLine("\n" + x0 + " denominator became 0");
}
else
{
Console.WriteLine("\n" + "Maximum number of iterations exceeded.");
}
}
static void Main(string[] args)
{
int[] precios = { 100, 200, 300 };
string[] productos = { "vaso", "plato", "cuchara" };
double resultado = 0;
for (int i = 0; i < productos.Length; i++)
{
resultado += Calculus.CalcularImpuesto(precios[i]);
Console.WriteLine("Precio: " + precios[i]);
Console.WriteLine("resultado: " + resultado);
}
Console.ReadKey();
}