public static ValueTerm IntegrateTrapezoid(FunctionTerm function, OrderedRange <double> bounds, int segmentCount)
{
if (segmentCount < 1)
{
throw new ArgumentOutOfRangeException("segmentCount");
}
ValueTerm segmentWidth = Terms.Constant(bounds.Length() / segmentCount);
IEnumerable <ValueTerm> values =
(
from segmentPosition in Scalars.GetIntermediateValuesSymmetric(bounds.Start, bounds.End, segmentCount)
select function.Apply(Terms.Constant(segmentPosition))
)
.ToArray();
return(Terms.Product
(
segmentWidth,
Terms.Sum
(
Enumerables.Concatenate
(
Enumerables.Create(Terms.Product(Terms.Constant(0.5), values.First())),
values.Skip(1).SkipLast(1),
Enumerables.Create(Terms.Product(Terms.Constant(0.5), values.Last()))
)
)
));
}
public static ValueTerm Apply(this FunctionTerm function, params ValueTerm[] parameters)
{
return(function.Apply((IEnumerable <ValueTerm>)parameters));
}