private void SetResult(EvaluationContext context, FunctionFoundEventArgs <Derivatives <Func <double> > > args, IFunction <double, double> doubleFunction)
{
var argumentCount = args.ArgumentCount;
var variableCount = 1;
for (var i = 0; i < argumentCount; i++)
{
variableCount = Math.Max(variableCount, args[i].Count);
}
var result = new DoubleDerivatives(variableCount);
var arguments = new Func <double> [argumentCount];
for (var i = 0; i < argumentCount; i++)
{
var iLocal = i;
arguments[i] = () => args[iLocal][0]();
}
result[0] = () =>
{
var argumentValues = arguments.Select(arg => arg()).ToArray();
return(doubleFunction.Logic(string.Empty, argumentValues, context));
};
if (doubleFunction is IDerivativeFunction <double, double> derivativeFunction)
{
var derivatives = new Lazy <Derivatives <Func <double> > >(() => derivativeFunction.Derivative(string.Empty, args, context));
for (var i = 1; i <= variableCount; i++)
{
var derivativeIndex = i;
if (IsDerivativeDefined(args, derivativeIndex))
{
result[i] = () => GetDerivativeValue(args, derivativeIndex, argumentCount, derivatives);
}
}
}
args.Result = result;
}
private double GetDerivativeValue(FunctionFoundEventArgs <Derivatives <Func <double> > > args, int derivativeIndex, int argumentCount, Lazy <Derivatives <Func <double> > > derivatives)
{
var result = 0.0;
for (var argumentIndex = 0; argumentIndex < argumentCount; argumentIndex++)
{
if (args[argumentIndex][derivativeIndex] != null)
{
var derivative = derivatives.Value[argumentIndex + 1];
if (derivative != null)
{
result += args[argumentIndex][derivativeIndex]() * derivative.Invoke();
}
}
}
return(result);
}
public Derivatives <Func <double> > Derivative(string image, FunctionFoundEventArgs <Derivatives <Func <double> > > args, EvaluationContext context)
{
return(GetDerivatives(args));
}
