public virtual double?[] getRoots(RealPolynomialFunction1D function)
{
ArgChecker.notNull(function, "function");
double[] coeffs = function.Coefficients;
int l = coeffs.Length - 1;
//JAVA TO C# CONVERTER NOTE: The following call to the 'RectangularArrays' helper class reproduces the rectangular array initialization that is automatic in Java:
//ORIGINAL LINE: double[][] hessianDeref = new double[l][l];
double[][] hessianDeref = RectangularArrays.ReturnRectangularDoubleArray(l, l);
for (int i = 0; i < l; i++)
{
hessianDeref[0][i] = -coeffs[l - i - 1] / coeffs[l];
for (int j = 1; j < l; j++)
{
hessianDeref[j][i] = 0;
if (i != l - 1)
{
hessianDeref[i + 1][i] = 1;
}
}
}
RealMatrix hessian = new Array2DRowRealMatrix(hessianDeref);
double[] d = (new EigenDecomposition(hessian)).RealEigenvalues;
double?[] result = new double?[d.Length];
for (int i = 0; i < d.Length; i++)
{
result[i] = d[i];
}
return(result);
}
//JAVA TO C# CONVERTER TODO TASK: Most Java annotations will not have direct .NET equivalent attributes:
//ORIGINAL LINE: @Test public void test()
public virtual void test()
{
//JAVA TO C# CONVERTER WARNING: The original Java variable was marked 'final':
//ORIGINAL LINE: final double[] r = new double[] {-RANDOM.nextDouble(), -RANDOM.nextDouble(), RANDOM.nextDouble(), RANDOM.nextDouble() };
double[] r = new double[] { -RANDOM.NextDouble(), -RANDOM.NextDouble(), RANDOM.NextDouble(), RANDOM.NextDouble() };
//JAVA TO C# CONVERTER WARNING: The original Java variable was marked 'final':
//ORIGINAL LINE: final double a0 = r[0] * r[1] * r[2] * r[3];
double a0 = r[0] * r[1] * r[2] * r[3];
//JAVA TO C# CONVERTER WARNING: The original Java variable was marked 'final':
//ORIGINAL LINE: final double a1 = r[0] * r[1] * r[2] + r[0] * r[1] * r[3] + r[0] * r[2] * r[3] + r[1] * r[2] * r[3];
double a1 = r[0] * r[1] * r[2] + r[0] * r[1] * r[3] + r[0] * r[2] * r[3] + r[1] * r[2] * r[3];
//JAVA TO C# CONVERTER WARNING: The original Java variable was marked 'final':
//ORIGINAL LINE: final double a2 = r[0] * r[1] + r[0] * r[2] + r[0] * r[3] + r[1] * r[2] + r[1] * r[3] + r[2] * r[3];
double a2 = r[0] * r[1] + r[0] * r[2] + r[0] * r[3] + r[1] * r[2] + r[1] * r[3] + r[2] * r[3];
//JAVA TO C# CONVERTER WARNING: The original Java variable was marked 'final':
//ORIGINAL LINE: final double a3 = r[0] + r[1] + r[2] + r[3];
double a3 = r[0] + r[1] + r[2] + r[3];
const double a4 = 1;
//JAVA TO C# CONVERTER WARNING: The original Java variable was marked 'final':
//ORIGINAL LINE: final com.opengamma.strata.math.impl.function.RealPolynomialFunction1D f = new com.opengamma.strata.math.impl.function.RealPolynomialFunction1D(new double[] {a0, a1, a2, a3, a4 });
RealPolynomialFunction1D f = new RealPolynomialFunction1D(new double[] { a0, a1, a2, a3, a4 });
//JAVA TO C# CONVERTER WARNING: The original Java variable was marked 'final':
//ORIGINAL LINE: final System.Nullable<double>[] roots = FINDER.getRoots(f);
double?[] roots = FINDER.getRoots(f);
Arrays.sort(roots);
//JAVA TO C# CONVERTER WARNING: The original Java variable was marked 'final':
//ORIGINAL LINE: final double[] expected = new double[r.length];
double[] expected = new double[r.Length];
for (int i = 0; i < r.Length; i++)
{
expected[i] = -r[i];
}
Arrays.sort(expected);
for (int i = 0; i < roots.Length; i++)
{
assertEquals(roots[i], expected[i], 1e-12);
}
}
