/// <inheritdoc/>
public override ExpNode Execute(MultiplicationOperNode node)
{
// TODO: Sinusoidal u substitutions
// TODO: Constants recognitions for v
Differentiator differentiator = new(_variable);
// \int{u'vwx} = uvwx - \int{uv'wx} - \int{uvw'x} - \int{uvwx'}
int partCount = node.ChildCount - 1;
// Get u and du
ExpNode du = node.GetChild(partCount);
ExpNode u = du.Clone().Execute(this);
// Get dvs and vs
ExpNode[] dvs = new ExpNode[partCount];
ExpNode[] vs = new ExpNode[partCount];
for (int i = 0; i < partCount; i++)
{
vs[i] = node.GetChild(i);
dvs[i] = vs[i].Clone().Execute(differentiator);
}
AdditionOperNode aNode = new();
// u*vs
MultiplicationOperNode mNode = new();
mNode.AddChild(u.Clone());
for (int i = 0; i < partCount; i++)
{
mNode.AddChild(vs[i].Clone());
}
aNode.AddChild(mNode);
// Combinatoric integrals
for (int i = 0; i < partCount; i++)
{
IntegralOperNode intNode = new();
mNode = new MultiplicationOperNode();
intNode.Variable = new VarValueNode(_variable);
mNode.AddChild(u.Clone());
for (int j = 0; j < partCount; j++)
{
if (i == j)
{
mNode.AddChild(dvs[j].Clone());
}
else
{
mNode.AddChild(vs[j].Clone());
}
}
intNode.AddChild(mNode);
aNode.AddChild(QuickOpers.Negative(intNode));
}
return(aNode);
}
/// <summary>
/// Splits an <see cref="MultiplicationOperNode"/> into terms and simplifies by common terms.
/// </summary>
/// <param name="node">The <see cref="MultiplicationOperNode"/> to simplify.</param>
/// <param name="simplifier">The <see cref="Simplifier"/> calling.</param>
/// <returns>The resulting <see cref="ExpNode"/>.</returns>
public static MultiplicationOperNode SimplfiyMTerms(MultiplicationOperNode node, Simplifier simplifier)
{
SortedSet <MultiplicativeTerm> mTerms = new();
for (int i = 0; i < node.ChildCount; i++)
{
MultiplicativeTerm mTerm = new(node.GetChild(i));
if (mTerms.TryGetValue(mTerm, out MultiplicativeTerm existingMTerm))
{
existingMTerm.AddToExponent(mTerm, simplifier);
}
else
{
mTerms.Add(mTerm);
}
}
node.ClearChildren();
foreach (var term in mTerms)
{
node.AddChild(term.AsExpNode());
}
return(node);
}
/// <inheritdoc/>
public override ExpNode Execute(MultiplicationOperNode node)
{
double valueProg = 1;
for (int i = 0; i < node.ChildCount; i++)
{
ExpNode simpleChild = node.GetChild(i).Execute(this);
if (simpleChild is NumericalValueNode nvNode)
{
valueProg *= nvNode.DoubleValue;
node.RemoveChild(i);
i--;
}
else if (simpleChild is MultiplicationOperNode mNode)
{
mNode.TransferChildren(node);
node.RemoveChild(i);
i--;
}
else
{
node.ReplaceChild(simpleChild, i);
}
}
// Anything multiplied by 0, is zero
if (valueProg == 0)
{
return(QuickOpers.MakeNumericalNode(0));
}
if (node.ChildCount == 0 || valueProg != 1)
{
node.AddChild(QuickOpers.MakeNumericalNode(valueProg));
}
MultiplicationHelpers.SimplfiyMTerms(node, this);
if (node.ChildCount == 0)
{
return(QuickOpers.MakeNumericalNode(0));
}
else if (node.ChildCount == 1)
{
return(node.GetChild(0));
}
node = MultiplicationHelpers.MultiplyScalarTensor(node, this);
if (node == null)
{
return(node);
}
return(MultiplicationHelpers.Distribute(node, this));
}