/// <summary>
/// Change the base of the group to the new base <paramref name="newBase"/>.
/// </summary>
/// <param name="newBase">the new base for the group</param>
public void ChangeBase(Permutation newBase)
{
var h = new PermutationGroup(newBase);
int firstDiffIndex = basePermutation.FirstIndexOfDifference(newBase);
for (int j = firstDiffIndex; j < size; j++)
{
for (int a = 0; a < size; a++)
{
Permutation g = permutations[j][a];
if (g != null)
{
h.Enter(g);
}
}
}
for (int j = 0; j < firstDiffIndex; j++)
{
for (int a = 0; a < size; a++)
{
Permutation g = permutations[j][a];
if (g != null)
{
int hj = h.basePermutation[j];
int x = g[hj];
h.permutations[j][x] = new Permutation(g);
}
}
}
this.basePermutation = new Permutation(h.basePermutation);
this.permutations = (Permutation[][])h.permutations.Clone();
}
public void EnterTest()
{
int size = 4;
PermutationGroup group = new PermutationGroup(size);
group.Enter(new Permutation(1, 0, 3, 2));
Assert.AreEqual(2, group.Order());
}
/// <summary>
/// Does the work of the class, that refines a coarse partition into a finer
/// one using the supplied automorphism group to prune the search.
/// </summary>
/// <param name="group">the automorphism group of the graph</param>
/// <param name="coarser">the partition to refine</param>
private void Refine(PermutationGroup group, Partition coarser)
{
int vertexCount = GetVertexCount();
Partition finer = equitableRefiner.Refine(coarser);
int firstNonDiscreteCell = finer.GetIndexOfFirstNonDiscreteCell();
if (firstNonDiscreteCell == -1)
{
firstNonDiscreteCell = vertexCount;
}
Permutation pi1 = new Permutation(firstNonDiscreteCell);
Result result = Result.Better;
if (bestExist)
{
pi1 = finer.SetAsPermutation(firstNonDiscreteCell);
result = CompareRowwise(pi1);
}
// partition is discrete
if (finer.Count == vertexCount)
{
if (!bestExist)
{
best = finer.ToPermutation();
first = finer.ToPermutation();
bestExist = true;
}
else
{
if (result == Result.Better)
{
best = new Permutation(pi1);
}
else if (result == Result.Equal)
{
group.Enter(pi1.Multiply(best.Invert()));
}
}
}
else
{
if (result != Result.Worse)
{
var blockCopy = finer.CopyBlock(firstNonDiscreteCell);
for (int vertexInBlock = 0; vertexInBlock < vertexCount; vertexInBlock++)
{
if (blockCopy.Contains(vertexInBlock))
{
Partition nextPartition = finer.SplitBefore(firstNonDiscreteCell, vertexInBlock);
this.Refine(group, nextPartition);
int[] permF = new int[vertexCount];
int[] invF = new int[vertexCount];
for (int i = 0; i < vertexCount; i++)
{
permF[i] = i;
invF[i] = i;
}
for (int j = 0; j <= firstNonDiscreteCell; j++)
{
int x = nextPartition.GetFirstInCell(j);
int i = invF[x];
int h = permF[j];
permF[j] = x;
permF[i] = h;
invF[h] = i;
invF[x] = j;
}
Permutation pPermF = new Permutation(permF);
group.ChangeBase(pPermF);
for (int j = 0; j < vertexCount; j++)
{
Permutation g = group[firstNonDiscreteCell, j];
if (g != null)
{
blockCopy.Remove(g[vertexInBlock]);
}
}
}
}
}
}
}