/// @param r double
/// @return DhbFunctionEvaluation.PolynomialFunction
public PolynomialFunction[] DivideWithRemainder(PolynomialFunction p)
{
PolynomialFunction[] answer = new PolynomialFunction[2];
int m = this.Degree;
int n = p.Degree;
if (m < n)
{
answer[0] = new PolynomialFunction(new double[] { 0 });
answer[1] = p;
return(answer);
}
double[] quotient = new double[m - n + 1];
double[] coef = new double[m + 1];
for (int k = 0; k <= m; k++)
{
coef[k] = _coefficients[k];
}
double norm = 1 / p[n];
for (int k = m - n; k >= 0; k--)
{
quotient[k] = coef[n + k] * norm;
for (int j = n + k - 1; j >= k; j--)
{
coef[j] -= quotient[k] * p[j - k];
}
}
double[] remainder = new double[n];
for (int k = 0; k < n; k++)
{
remainder[k] = coef[k];
}
answer[0] = new PolynomialFunction(quotient);
answer[1] = new PolynomialFunction(remainder);
return(answer);
}
/// @param desiredPrecision double
/// @return double[]
public double[] Roots(double desiredPrecision)
{
PolynomialFunction dp = this.Derivative();
double start = 0;
Random random = new Random();
while (Math.Abs(dp.Value(start)) < desiredPrecision)
{
start = random.NextDouble();
}
PolynomialFunction p = this;
NewtonZeroFinder rootFinder = new NewtonZeroFinder(this, dp, start);
rootFinder.DesiredPrecision = desiredPrecision;
List <double> rootCollection = new List <double>(Degree);
while (true)
{
rootFinder.Evaluate();
if (!rootFinder.HasConverged)
{
break;
}
double r = rootFinder.Result;
rootCollection.Add(r);
p = p.Deflate(r);
if (p.Degree == 0)
{
break;
}
rootFinder.Function = p;
try { rootFinder.Derivative = p.Derivative(); }
catch (ArgumentException) { };
}
return(rootCollection.ToArray());
}
