/// <summary>
/// Verifies that current subcircuit with given nodes as terminals represents valid SPICE subcircuit. That is:
/// there are no floating nodes and there is a DC path between any two nodes not going through ground.
/// </summary>
/// <param name="terminals"></param>
private CircuitTopologyException ValidateSubcircuit_Internal(int[] terminals)
{
// ground node must not be external terminal
if (terminals == null)
{
throw new ArgumentNullException(nameof(terminals));
}
if (terminals.Length == 0)
{
throw new ArgumentException("Subcircuit must have at least one terminal node.");
}
if (terminals.Any(n => n <= 0))
{
throw new ArgumentOutOfRangeException("Terminals of Subcircuit must have positive ids.");
}
if (terminals.Any(n => n >= NodeCount))
{
throw new ArgumentOutOfRangeException("There is no node with given id.");
}
if (validatedCircuit)
{
return(circuitException);
}
var neighbourghs = CircuitBuilderHelpers.GetNeighbourghs(NodeCount, Devices);
neighbourghs[0].Clear(); // ignore connections to the ground node
var components = CircuitBuilderHelpers.GetComponents(neighbourghs);
components.RemoveAll(c => c[0] == 0); // remove ground component
if (components.Count != 1) // incorrectly connected
{
return(new NotConnectedSubcircuitException(components));
}
var branches = devices.SelectMany(e => e.GetBranchMetadata()).ToArray();
var cycle = GetVoltageCicrle(branches);
return(cycle != null ? new VoltageBranchCycleException(cycle) : null);
}
private IEnumerable <ICircuitDefinitionDevice> GetCurrentCutset(CircuitBranchMetadata[] branches)
{
var currentBranches = branches.Where(b => b.BranchType == BranchType.CurrentDefined).ToArray();
var neighbourghs = CircuitBuilderHelpers.GetNeighbourghs(NodeCount, devices);
// remove current defined branches from the graph
var nonCurrentElems = new HashSet <ICircuitDefinitionDevice>(devices);
foreach (var e in currentBranches.Select(b => b.Device))
{
nonCurrentElems.Remove(e);
}
foreach (var branch in currentBranches)
{
if (nonCurrentElems.Any(e =>
e.ConnectedNodes.Contains(branch.N1) && e.ConnectedNodes.Contains(branch.N2)))
{
continue; // some node bridges the same connection as this branch
}
neighbourghs[branch.N1].Remove(branch.N2);
neighbourghs[branch.N2].Remove(branch.N1);
}
var components = CircuitBuilderHelpers.GetComponents(neighbourghs);
// get indexes of components for faster lookup
var componentIndexes = new int[NodeCount];
for (var i = 0; i < components.Count; i++)
{
foreach (var n in components[i])
{
componentIndexes[n] = i;
}
}
// throw away branches that do not connect nodes from different components
var result = currentBranches
.Where(b => componentIndexes[b.N1] != componentIndexes[b.N2]).Select(b => b.Device).ToArray();
return(result.Length > 0 ? result : null);
}