/// <summary>
/// Solves a set of coupled, conservative second order ordinary differential equation initial value problems using the given settings.
/// </summary>
/// <param name="rhs">The right hand side function.</param>
/// <param name="x0">The initial value of the independent variable.</param>
/// <param name="y0">The initial values of the functions.</param>
/// <param name="yPrime0">The intial values of the functions' derivatives.</param>
/// <param name="x1">The final value of the independent variable.</param>
/// <param name="settings">The settings to use when solving the problem.</param>
/// <returns>The solution, including the final value of the functions and their derivatives.</returns>
/// <exception cref="ArgumentNullException"><paramref name="rhs"/>, <paramref name="y0"/>, <paramref name="yPrime0"/>,
/// or <paramref name="settings"/> is <see langword="null"/>.</exception>
/// <exception cref="DimensionMismatchException"><paramref name="y0"/> and <paramref name="yPrime0"/> do not have the same
/// dimension.</exception>
/// <exception cref="NonconvergenceException">The ODE could not be integrated to the required precision before exhausting
/// the maximum allowed number of <paramref name="rhs"/>evaluations.</exception>
/// <remarks>
/// <para>For information on conservative ODEs, see <see cref="FunctionMath.IntegrateConservativeOde(Func{double, double, double}, double, double, double, double, OdeEvaluationSettings)"/>.</para>
/// </remarks>
public static MultiOdeResult IntegrateConservativeOde(Func <double, IList <double>, IList <double> > rhs, double x0, IList <double> y0, IList <double> yPrime0, double x1, MultiOdeEvaluationSettings settings)
{
if (rhs == null)
{
throw new ArgumentNullException(nameof(rhs));
}
if (y0 == null)
{
throw new ArgumentNullException(nameof(y0));
}
if (yPrime0 == null)
{
throw new ArgumentNullException(nameof(yPrime0));
}
if (settings == null)
{
throw new ArgumentNullException(nameof(settings));
}
if (y0.Count != yPrime0.Count)
{
throw new DimensionMismatchException();
}
FunctionMath.SetOdeDefaults(settings);
MultiStoermerEngine engine = new MultiStoermerEngine(rhs, x0, y0, yPrime0, settings);
BulrischStoerStrategy strategy = new BulrischStoerStrategy(engine);
strategy.IntegrateTo(x1);
return(engine.GetResult());
}
public MultiBulrischStoerEngine(Func <double, IList <double>, IList <double> > rhs, double x, IList <double> y, MultiOdeEvaluationSettings settings) : base(rhs, x, settings)
{
Debug.Assert(rhs != null);
Debug.Assert(y != null);
Debug.Assert(settings != null);
Y = new double[y.Count];
y.CopyTo(Y, 0);
YPrime = new double[y.Count];
Evaluate(X, Y).CopyTo(YPrime, 0);
ComputeInitialStep();
extrapolators = new NevilleExtrapolator[y.Count];
for (int i = 0; i < extrapolators.Length; i++)
{
extrapolators[i] = new NevilleExtrapolator(N.Length);
}
}
public MultiStoermerEngine(Func <double, IList <double>, IList <double> > rhs, double x, IList <double> y, IList <double> yPrime, MultiOdeEvaluationSettings settings) : base(rhs, x, settings)
{
Debug.Assert(rhs != null);
Debug.Assert(y != null);
Debug.Assert(yPrime != null);
Debug.Assert(settings != null);
Debug.Assert(y.Count == yPrime.Count);
dimension = y.Count;
Y = new double[dimension];
y.CopyTo(Y, 0);
YPrime = new double[dimension];
yPrime.CopyTo(YPrime, 0);
YPrimePrime = new double[dimension];
Evaluate(x, y).CopyTo(YPrimePrime, 0);
ComputeInitialStep();
yExtrapolators = new NevilleExtrapolator[y.Count];
yPrimeExtrapolators = new NevilleExtrapolator[yPrime.Count];
for (int i = 0; i < y.Count; i++)
{
yExtrapolators[i] = new NevilleExtrapolator(N.Length);
yPrimeExtrapolators[i] = new NevilleExtrapolator(N.Length);
}
}
public MultiOdeEngine(Func <double, IList <double>, IList <double> > rhs, double x, MultiOdeEvaluationSettings settings) : base(x)
{
Debug.Assert(rhs != null);
Debug.Assert(settings != null);
this.rhs = rhs;
this.settings = settings;
}