/// <summary>
/// Compute the n-th stage integral of trapezoid rule. This function
/// should only be called by API <code>integrate()</code> in the package.
/// To save time it does not verify arguments - caller does.
/// <para>
/// The interval is divided equally into 2^n sections rather than an
/// arbitrary m sections because this configuration can best utilize the
/// already computed values.</para>
/// </summary>
/// <param name="baseIntegrator"> integrator holding integration parameters </param>
/// <param name="n"> the stage of 1/2 refinement, n = 0 is no refinement </param>
/// <returns> the value of n-th stage integral </returns>
/// <exception cref="TooManyEvaluationsException"> if the maximal number of evaluations
/// is exceeded. </exception>
internal virtual double Stage(BaseAbstractUnivariateIntegrator baseIntegrator, int n)
{
if (n == 0)
{
double max = baseIntegrator.Max;
double min = baseIntegrator.Min;
this.s = 0.5 * (max - min) * (baseIntegrator.ComputeObjectiveValue(min) + baseIntegrator.ComputeObjectiveValue(max));
return(this.s);
}
else
{
long np = 1L << (n - 1); // number of new points in this stage
double sum = 0;
double max = baseIntegrator.Max;
double min = baseIntegrator.Min;
// spacing between adjacent new points
double spacing = (max - min) / np;
double x = min + 0.5 * spacing; // the first new point
for (long i = 0; i < np; i++)
{
sum += baseIntegrator.ComputeObjectiveValue(x);
x += spacing;
}
// add the new sum to previously calculated result
this.s = 0.5 * (this.s + sum * spacing);
return(this.s);
}
}
/// <summary>
/// Compute the n-th stage integral of trapezoid rule. This function
/// should only be called by API <code>integrate()</code> in the package.
/// To save time it does not verify arguments - caller does.
/// <para>
/// The interval is divided equally into 2^n sections rather than an
/// arbitrary m sections because this configuration can best utilize the
/// already computed values.</para>
/// </summary>
/// <param name="baseIntegrator"> integrator holding integration parameters </param>
/// <param name="n"> the stage of 1/2 refinement, n = 0 is no refinement </param>
/// <returns> the value of n-th stage integral </returns>
/// <exception cref="TooManyEvaluationsException"> if the maximal number of evaluations
/// is exceeded. </exception>
//JAVA TO C# CONVERTER WARNING: 'final' parameters are not available in .NET:
//ORIGINAL LINE: double stage(final BaseAbstractUnivariateIntegrator baseIntegrator, final int n) throws org.apache.commons.math3.exception.TooManyEvaluationsException
internal virtual double Stage(BaseAbstractUnivariateIntegrator baseIntegrator, int n)
{
if (n == 0)
{
//JAVA TO C# CONVERTER WARNING: The original Java variable was marked 'final':
//ORIGINAL LINE: final double max = baseIntegrator.getMax();
double max = baseIntegrator.GetMax();
//JAVA TO C# CONVERTER WARNING: The original Java variable was marked 'final':
//ORIGINAL LINE: final double min = baseIntegrator.getMin();
double min = baseIntegrator.GetMin();
s = 0.5 * (max - min) * (baseIntegrator.ComputeObjectiveValue(min) + baseIntegrator.ComputeObjectiveValue(max));
return(s);
}
else
{
//JAVA TO C# CONVERTER WARNING: The original Java variable was marked 'final':
//ORIGINAL LINE: final long np = 1L << (n-1);
long np = 1L << (n - 1); // number of new points in this stage
double sum = 0;
//JAVA TO C# CONVERTER WARNING: The original Java variable was marked 'final':
//ORIGINAL LINE: final double max = baseIntegrator.getMax();
double max = baseIntegrator.GetMax();
//JAVA TO C# CONVERTER WARNING: The original Java variable was marked 'final':
//ORIGINAL LINE: final double min = baseIntegrator.getMin();
double min = baseIntegrator.GetMin();
// spacing between adjacent new points
//JAVA TO C# CONVERTER WARNING: The original Java variable was marked 'final':
//ORIGINAL LINE: final double spacing = (max - min) / np;
double spacing = (max - min) / np;
double x = min + 0.5 * spacing; // the first new point
for (long i = 0; i < np; i++)
{
sum += baseIntegrator.ComputeObjectiveValue(x);
x += spacing;
}
// add the new sum to previously calculated result
s = 0.5 * (s + sum * spacing);
return(s);
}
}
