internal Arm(ConstantSet constants, ArmSpec spec)
{
IList <NodePairSpec> nodePairs = spec.NodePair;
NodeSpec upperFirstSpec = nodePairs[0].Upper;
NodeSpec lowerFirstSpec = nodePairs[0].Lower;
DominatedNode lowerFirst = new DominatedNode(lowerFirstSpec.Mass, Vector2D.FromDuple(lowerFirstSpec.Position), Vector2D.FromDuple(lowerFirstSpec.Velocity));
Node upperFirst = new RotationDominantNode(upperFirstSpec.Mass, Vector2D.FromDuple(upperFirstSpec.Position), Vector2D.FromDuple(upperFirstSpec.Velocity), lowerFirst);
UpperNodes = Enumerable
.Repeat(upperFirst, 1)
.Concat(nodePairs.Skip(1).Select(np => new Node(np.Upper)))
.ToArray();
LowerNodes = Enumerable
.Repeat(lowerFirst as Node, 1)
.Concat(nodePairs.Skip(1).Select(np => new Node(np.Lower)))
.ToArray();
Nodes = UpperNodes.Concat(LowerNodes).ToArray();
Compartments = UpperNodes
.Select((node, index)
=> (index == 0) ? null : new Compartment(constants, UpperNodes[index - 1], UpperNodes[index], LowerNodes[index], LowerNodes[index - 1]))
.Skip(1)
.ToArray();
}
public Node(NodeSpec spec)
: this(spec.Mass, Vector2D.FromDuple(spec.Position), Vector2D.FromDuple(spec.Velocity))
{
}