/// <inheritdoc/>
public override ExpNode Execute(VectorProductOperNode node)
{
// Verify left and right child are two multiplyable vectors.
if (node.LeftChild is TensorNode vector1 && vector1.DimensionCount == 1 &&
node.RightChild is TensorNode vector2 && vector2.DimensionCount == 1 &&
vector1.SizeIdentity == vector2.SizeIdentity)
{
int size = vector1.GetDimensionSize(1);
switch (node.ProductMethod)
{
case VectorProductMethod.DOT:
ExpNode[] terms = new ExpNode[size];
for (int i = 0; i < size; i++)
{
terms[i] = QuickOpers.Multiply(vector1.GetChild(i), vector2.GetChild(i));
}
return(QuickOpers.Sum(terms).Execute(this));
case VectorProductMethod.CROSS: // TODO: Convert to matrix notation for determinant
default:
return(node);
}
}
return(HandleError(new CannotMultiplyTensors(this, node)));
}
/// <summary>
/// Creates a new <see cref="VectorProjOperNode"/> projecting <paramref name="a"/> onto <paramref name="b"/>.
/// </summary>
/// <param name="a">The <see cref="TensorNode"/> to project from.</param>
/// <param name="b">The <see cref="TensorNode"/> to project onto.</param>
/// <returns>A new <see cref="VectorProjOperNode"/> as <paramref name="a"/> projected onto <paramref name="b"/>.</returns>
public static VectorProductOperNode DotProduct(TensorNode a, TensorNode b)
{
VectorProductOperNode node = new VectorProductOperNode(VectorProductMethod.DOT);
node.AddChild(a);
node.AddChild(b);
return(node);
}
/// <inheritdoc/>
public override ExpNode Execute(VectorProjOperNode node)
{
if (node.LeftChild.AreEqualSizeVectors(node.RightChild, out TensorNode a, out TensorNode b))
{
VectorProductOperNode adotb = QuickOpers.DotProduct(a, (TensorNode)b.Clone());
BOperNode bdotb = QuickOpers.DotProduct((TensorNode)b.Clone(), (TensorNode)b.Clone());
return(QuickOpers.Multiply(b, adotb, QuickOpers.Reciprical(bdotb)).Execute(this));
}
return(HandleError(new CannotVectorProject(this, node)));
}
public void DotProduct()
{
// Parse
DefaultParser parser = new DefaultParser();
VectorProductOperNode node = new VectorProductOperNode(VectorProductMethod.DOT);
parser.ParseString("<2,1,3>");
node.AddChild(parser.Tree.Root);
parser = new DefaultParser();
parser.ParseString("<1,2,3>");
node.AddChild(parser.Tree.Root);
// Simplify
Simplifier simplifier = new Simplifier();
ExpNode exp_result = node.Execute(simplifier);
// Print
DefaultPrinter printer = new DefaultPrinter();
string str_result = exp_result.Print(printer);
// Compare
Assert.IsTrue(str_result == "13");
}
/// <summary> /// Executes operation on a <see cref="VectorProductOperNode"/>. /// </summary> /// <param name="node">The <see cref="VectorProductOperNode"/> to execute operation on.</param> /// <returns>The result of the operation on a <see cref="VectorProductOperNode"/>.</returns> public virtual ExpNode Execute(VectorProductOperNode node) => Execute((BOperNode)node);
