/// <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));
}
/// <summary>
/// Multiplies a tensor by scalars.
/// </summary>
/// <param name="node">The <see cref="MultiplicationOperNode"/> to simplify.</param>
/// <param name="simplifier">The <see cref="Simplifier"/> calling.</param>
/// <returns>The resuling <see cref="MultiplicationOperNode"/>.</returns>
public static MultiplicationOperNode MultiplyScalarTensor(MultiplicationOperNode node, Simplifier simplifier)
{
TensorNode tensor1 = null;
int ti = -1;
for (int i = 0; i < node.ChildCount; i++)
{
if (i == ti)
{
continue;
}
if (node.GetChild(i) is TensorNode tensor2)
{
if (tensor1 != null)
{
if (i < ti)
{
TensorNode swap = tensor1;
tensor1 = tensor2;
tensor2 = swap;
}
if (!tensor1.CanMatrixMultiply(tensor2))
{
return((MultiplicationOperNode)simplifier.HandleError(new CannotMultiplyTensors(simplifier, node, $"Tensor nodes of size {tensor1.SizeIdentity} and {tensor2.SizeIdentity} could not be multiplied.")));
}
}
else
{
tensor1 = tensor2;
ti = i;
i = -1;
}
}
else
{
if (tensor1 != null)
{
for (int j = 0; j < tensor1.ChildCount; j++)
{
ExpNode simpleChild = QuickOpers.Multiply(tensor1.GetChild(j), node.GetChild(i)).Execute(simplifier);
tensor1.ReplaceChild(simpleChild, j);
}
node.RemoveChild(i);
if (i < ti)
{
ti--;
}
i--;
}
}
}
return(node);
}