public static QuiverWithPotential <int> GetTriangleQP(int numRows, int firstVertex = DefaultFirstVertex)
{
if (!TriangleParameterIsValid(numRows))
{
throw new ArgumentOutOfRangeException(nameof(numRows));
}
if (numRows == 1)
{
var quiver = UsefulQuivers.GetTriangleQuiver(numRows, firstVertex);
return(new QuiverWithPotential <int>(quiver, new Potential <int>()));
}
var potential = new Potential <int>();
var curRowVertices = new List <int>()
{
firstVertex
};
int nextVertex = firstVertex + 1;
for (int rowIndex = 1; rowIndex <= numRows - 1; rowIndex++) // 1-based row index
{
var nextRowVertices = Enumerable.Range(nextVertex, rowIndex + 1).ToList();
nextVertex += rowIndex + 1;
// (2*rowIndex - 1) triangles to add. Draw a small triangle QP to realize that
// the cycles below are the ones to add.
for (int indexInRow = 0; indexInRow < rowIndex; indexInRow++)
{
var cycleVertices = new int[] { curRowVertices[indexInRow], nextRowVertices[indexInRow + 1], nextRowVertices[indexInRow], curRowVertices[indexInRow] };
potential = potential.AddCycle(new DetachedCycle <int>(cycleVertices), +1); // Positive for clockwise cycles.
}
for (int indexInRow = 0; indexInRow < rowIndex - 1; indexInRow++)
{
var cycleVertices = new int[] { curRowVertices[indexInRow + 1], curRowVertices[indexInRow], nextRowVertices[indexInRow + 1], curRowVertices[indexInRow + 1] };
potential = potential.AddCycle(new DetachedCycle <int>(cycleVertices), -1); // Negative for counterclockwise cycles.
}
curRowVertices = nextRowVertices;
}
var qp = new QuiverWithPotential <int>(potential);
return(qp);
}
/// <summary>
///
/// </summary>
/// <param name="numRows">The number of rows of vertices.</param>
/// <param name="firstVertex"></param>
/// <returns></returns>
public static QuiverWithPotential <int> GetSquareQP(int numRows, int firstVertex = DefaultFirstVertex)
{
if (!SquareParameterIsValid(numRows))
{
throw new ArgumentOutOfRangeException(nameof(numRows));
}
int numVerticesInRow = numRows;
int numVertices = numVerticesInRow * numRows;
if (numRows == 1)
{
var quiver = UsefulQuivers.GetSquareQuiver(numRows, firstVertex);
return(new QuiverWithPotential <int>(quiver, new Potential <int>()));
}
var potential = new Potential <int>();
for (int rowIndex = 0; rowIndex < numRows - 1; rowIndex++)
{
var curRow = GetVerticesInSquareQPRow(numRows, rowIndex, firstVertex).ToList();
var nextRow = GetVerticesInSquareQPRow(numRows, rowIndex + 1, firstVertex).ToList();
for (int indexInRow = 0; indexInRow < numVerticesInRow - 1; indexInRow++)
{
int sign = (rowIndex + indexInRow).Modulo(2) == 0 ? +1 : -1;
var cycleVertices = sign == +1 ?
new int[] { curRow[indexInRow], curRow[indexInRow + 1], nextRow[indexInRow + 1], nextRow[indexInRow], curRow[indexInRow] } :
new int[] { curRow[indexInRow + 1], curRow[indexInRow], nextRow[indexInRow], nextRow[indexInRow + 1], curRow[indexInRow + 1] };
potential = potential.AddCycle(new DetachedCycle <int>(cycleVertices), sign);
}
}
var qp = new QuiverWithPotential <int>(potential);
return(qp);
}
public static QuiverWithPotential <int> GetPointedFlowerQP(int numPeriods, int firstVertex = DefaultFirstVertex)
{
if (!PointedFlowerParameterIsValid(numPeriods))
{
throw new ArgumentOutOfRangeException(nameof(numPeriods));
}
int numLayers = UsefulQuivers.GetNumberOfLayersInPointedFlowerQuiver(numPeriods);
int numVerticesInFullInnerLayer = 2 * numPeriods;
int numVerticesInOuterLayer = 3 * numPeriods;
var potential = new Potential <int>();
if (numLayers == 2)
{
int centerVertex = GetLayerVertices(0).Single();
var nextLayer = GetLayerVertices(1);
for (int periodIndex = 0; periodIndex < numPeriods; periodIndex++)
{
int indexInNextLayer = 3 * periodIndex;
// Square
var positiveCycleVertices = new int[] { centerVertex, nextLayer[indexInNextLayer], nextLayer[indexInNextLayer + 1], nextLayer[indexInNextLayer + 2], centerVertex };
// Triangle
var negativeCycleVertices = new int[] { centerVertex, nextLayer[indexInNextLayer + 3], nextLayer[indexInNextLayer + 2], centerVertex };
potential = potential.AddCycle(new DetachedCycle <int>(positiveCycleVertices), +1);
potential = potential.AddCycle(new DetachedCycle <int>(negativeCycleVertices), -1);
}
return(new QuiverWithPotential <int>(potential));
}
// Polygons between first and second layer
{
int centerVertex = GetLayerVertices(0).Single();
var nextLayer = GetLayerVertices(1);
for (int periodIndex = 0; periodIndex < numPeriods; periodIndex++)
{
int indexInNextLayer = 2 * periodIndex;
// Triangles
var positiveCycleVertices = new int[] { centerVertex, nextLayer[indexInNextLayer], nextLayer[indexInNextLayer + 1], centerVertex };
var negativeCycleVertices = new int[] { centerVertex, nextLayer[indexInNextLayer + 2], nextLayer[indexInNextLayer + 1], centerVertex };
potential = potential.AddCycle(new DetachedCycle <int>(positiveCycleVertices), +1);
potential = potential.AddCycle(new DetachedCycle <int>(negativeCycleVertices), -1);
}
}
// Cobweb layers
for (int layerIndex = 1; layerIndex < numLayers - 2; layerIndex++) // 0-based layer index
{
var curLayer = GetLayerVertices(layerIndex);
var nextLayer = GetLayerVertices(layerIndex + 1);
for (int indexInLayer = 0; indexInLayer < numVerticesInFullInnerLayer; indexInLayer++)
{
int sign = (layerIndex + indexInLayer).Modulo(2) == 0 ? +1 : -1;
var squareVertices = sign == +1 ?
new int[] { curLayer[indexInLayer + 1], curLayer[indexInLayer], nextLayer[indexInLayer], nextLayer[indexInLayer + 1], curLayer[indexInLayer + 1] } :
new int[] { curLayer[indexInLayer], curLayer[indexInLayer + 1], nextLayer[indexInLayer + 1], nextLayer[indexInLayer], curLayer[indexInLayer] };
potential = potential.AddCycle(new DetachedCycle <int>(squareVertices), sign);
}
}
// Outermost layer of polygons
{
int layerIndex = numLayers - 2;
var curLayer = GetLayerVertices(layerIndex);
var nextLayer = GetLayerVertices(layerIndex + 1);
for (int indexInPeriod = 0; indexInPeriod < numPeriods; indexInPeriod++)
{
// Add pentagon
int indexInPenultimateLayer = 2 * indexInPeriod;
int indexInUltimateLayer = 3 * indexInPeriod;
int pentagonSign = layerIndex.Modulo(2) == 0 ? +1 : -1; // Remember that layerIndex is the index of the *penultimate* layer
var pentagonVertices = pentagonSign == +1 ?
new int[] { curLayer[indexInPenultimateLayer + 1], curLayer[indexInPenultimateLayer], nextLayer[indexInUltimateLayer], nextLayer[indexInUltimateLayer + 1], nextLayer[indexInUltimateLayer + 2], curLayer[indexInPenultimateLayer + 1] } :
new int[] { curLayer[indexInPenultimateLayer], curLayer[indexInPenultimateLayer + 1], nextLayer[indexInUltimateLayer + 2], nextLayer[indexInUltimateLayer + 1], nextLayer[indexInUltimateLayer], curLayer[indexInPenultimateLayer] };
potential = potential.AddCycle(new DetachedCycle <int>(pentagonVertices), pentagonSign);
// Add square
int squareSign = -pentagonSign;
indexInPenultimateLayer += 1;
indexInUltimateLayer += 2;
var squareVertices = squareSign == +1 ?
new int[] { curLayer[indexInPenultimateLayer + 1], curLayer[indexInPenultimateLayer], nextLayer[indexInUltimateLayer], nextLayer[indexInUltimateLayer + 1], curLayer[indexInPenultimateLayer + 1] } :
new int[] { curLayer[indexInPenultimateLayer], curLayer[indexInPenultimateLayer + 1], nextLayer[indexInUltimateLayer + 1], nextLayer[indexInUltimateLayer], curLayer[indexInPenultimateLayer] };
potential = potential.AddCycle(new DetachedCycle <int>(squareVertices), squareSign);
}
}
var qp = new QuiverWithPotential <int>(potential);
return(qp);
CircularList <int> GetLayerVertices(int layerIndex)
=> new CircularList <int>(GetVerticesInPointedFlowerQPLayer(numPeriods, layerIndex, firstVertex));
}
public static int GetNumberOfLayersInPointedFlowerQP(int numPeriods) => UsefulQuivers.GetNumberOfLayersInPointedFlowerQuiver(numPeriods);
public static bool PointedFlowerParameterIsValid(int numPeriods) => UsefulQuivers.PointedFlowerParameterIsValid(numPeriods);
public static IEnumerable <IEnumerable <int> > GetPeriodsOfEvenFlowerType2QP(int numVerticesInCenterPolygon, int firstVertex = DefaultFirstVertex) => UsefulQuivers.GetPeriodsOfEvenFlowerType2Quiver(numVerticesInCenterPolygon, firstVertex);
public static IEnumerable <int> GetVerticesInSquareQPRow(int numRows, int rowIndex, int firstVertex = DefaultFirstVertex) => UsefulQuivers.GetVerticesInSquareQuiverRow(numRows, rowIndex, firstVertex);
public static IEnumerable <int> GetVerticesInTriangleQPRow(int rowIndex, int firstVertex = DefaultFirstVertex) => UsefulQuivers.GetVerticesInTriangleQuiverRow(rowIndex, firstVertex);
public static bool GeneralizedCobwebParameterIsValid(int numVerticesInCenterPolygon, int numLayers) => UsefulQuivers.GeneralizedCobwebParameterIsValid(numVerticesInCenterPolygon, numLayers);
public static bool EvenFlowerType2ParameterIsValid(int numVerticesInCenterPolygon) => UsefulQuivers.EvenFlowerType2ParameterIsValid(numVerticesInCenterPolygon);
public static bool TriangleParameterIsValid(int numRows) => UsefulQuivers.TriangleParameterIsValid(numRows);
public static int GetNumberOfLayersInOddFlowerQP(int numVerticesInCenterPolygon) => UsefulQuivers.GetNumberOfLayersInOddFlowerQuiver(numVerticesInCenterPolygon);
public static bool OddFlowerParameterIsValid(int numVerticesInCenterPolygon) => UsefulQuivers.OddFlowerParameterIsValid(numVerticesInCenterPolygon);
public static bool CycleParameterIsValid(int numVertices) => UsefulQuivers.CycleParameterIsValid(numVertices);
public static bool CobwebParameterIsValid(int numVerticesInCenterPolygon) => UsefulQuivers.CobwebParameterIsValid(numVerticesInCenterPolygon);
public static IEnumerable <int> GetVerticesInPointedFlowerQPLayer(int numPeriods, int layerIndex, int firstVertex = DefaultFirstVertex) => UsefulQuivers.GetVerticesInPointedFlowerQuiverLayer(numPeriods, layerIndex, firstVertex);
public static IEnumerable <IEnumerable <int> > GetPeriodsOfPointedFlowerQPWithoutFixedPoint(int numPeriods, int firstVertex = DefaultFirstVertex) => UsefulQuivers.GetPeriodsOfPointedFlowerQuiverWithoutFixedPoint(numPeriods, firstVertex);
public static int GetNumberOfLayersInEvenFlowerType2QP(int numVerticesInCenterPolygon) => UsefulQuivers.GetNumberOfLayersInEvenFlowerType2Quiver(numVerticesInCenterPolygon);
public static IEnumerable <int> GetVerticesInGeneralizedCobwebQPLayer(int numVerticesInCenterPolygon, int numLayers, int layerIndex, int firstVertex = DefaultFirstVertex) => UsefulQuivers.GetVerticesInGeneralizedCobwebQuiverLayer(numVerticesInCenterPolygon, numLayers, layerIndex, firstVertex);
public static QuiverWithPotential <int> GetEvenFlowerType2QP(int numVerticesInCenterPolygon, int firstVertex = DefaultFirstVertex)
{
if (!EvenFlowerType2ParameterIsValid(numVerticesInCenterPolygon))
{
throw new ArgumentOutOfRangeException(nameof(numVerticesInCenterPolygon));
}
int numLayers = UsefulQuivers.GetNumberOfLayersInEvenFlowerType2Quiver(numVerticesInCenterPolygon);
int numVerticesInFullInnerLayer = 2 * numVerticesInCenterPolygon;
int numVerticesInOuterLayer = 3 * numVerticesInCenterPolygon;
var potential = new Potential <int>();
// Center polygon
potential = potential.AddCycle(new DetachedCycle <int>(Enumerable.Range(firstVertex, numVerticesInCenterPolygon).AppendElement(firstVertex)), +1);
// Full inner layers
if (numLayers > 2)
{
// First layer (the squares and triangles between the first and second layers)
var curLayer = GetLayerVertices(0);
var nextLayer = GetLayerVertices(1);
for (int indexInLayer = 0; indexInLayer < numVerticesInCenterPolygon; indexInLayer++)
{
var triangleVertices = new int[] { curLayer[indexInLayer], nextLayer[2 * indexInLayer - 1], nextLayer[2 * indexInLayer], curLayer[indexInLayer] };
potential = potential.AddCycle(new DetachedCycle <int>(triangleVertices), +1);
var squareVertices = new int[] { curLayer[indexInLayer], curLayer[indexInLayer + 1], nextLayer[2 * indexInLayer + 1], nextLayer[2 * indexInLayer], curLayer[indexInLayer] };
potential = potential.AddCycle(new DetachedCycle <int>(squareVertices), -1);
}
// Remaining layers (only squares)
for (int layerIndex = 1; layerIndex < numLayers - 2; layerIndex++) // 0-based layer index
{
curLayer = GetLayerVertices(layerIndex);
nextLayer = GetLayerVertices(layerIndex + 1);
for (int indexInLayer = 0; indexInLayer < numVerticesInFullInnerLayer; indexInLayer++)
{
int sign = (layerIndex + indexInLayer).Modulo(2) == 1 ? +1 : -1;
var squareVertices = sign == +1 ?
new int[] { curLayer[indexInLayer + 1], curLayer[indexInLayer], nextLayer[indexInLayer], nextLayer[indexInLayer + 1], curLayer[indexInLayer + 1] } :
new int[] { curLayer[indexInLayer], curLayer[indexInLayer + 1], nextLayer[indexInLayer + 1], nextLayer[indexInLayer], curLayer[indexInLayer] };
potential = potential.AddCycle(new DetachedCycle <int>(squareVertices), sign);
}
}
}
// Outer layer
{
int layerIndex = numLayers - 2;
var curLayer = GetLayerVertices(layerIndex);
var nextLayer = GetLayerVertices(layerIndex + 1);
if (numLayers == 2)
{
// Add squares and diamonds in this degenerate case
for (int indexInLayer = 0; indexInLayer < curLayer.Count; indexInLayer++)
{
var diamondVertices = new int[] { curLayer[indexInLayer], nextLayer[3 * indexInLayer - 2], nextLayer[3 * indexInLayer - 1], nextLayer[3 * indexInLayer], curLayer[indexInLayer] };
potential = potential.AddCycle(new DetachedCycle <int>(diamondVertices), +1);
var squareVertices = new int[] { curLayer[indexInLayer], curLayer[indexInLayer + 1], nextLayer[3 * indexInLayer + 1], nextLayer[3 * indexInLayer], curLayer[indexInLayer] };
potential = potential.AddCycle(new DetachedCycle <int>(squareVertices), -1);
}
}
else
{
// Add squares and pentagons in the non-degenerate case
for (int indexInCenterLayer = 0; indexInCenterLayer < numVerticesInCenterPolygon; indexInCenterLayer++)
{
// Add square
int indexInPenultimateLayer = 2 * indexInCenterLayer;
int indexInUltimateLayer = 3 * indexInCenterLayer;
int squareSign = layerIndex.Modulo(2) == 1 ? +1 : -1; // Remember that layerIndex is the index of the *penultimate* layer
var squareVertices = squareSign == +1 ?
new int[] { curLayer[indexInPenultimateLayer + 1], curLayer[indexInPenultimateLayer], nextLayer[indexInUltimateLayer], nextLayer[indexInUltimateLayer + 1], curLayer[indexInPenultimateLayer + 1] } :
new int[] { curLayer[indexInPenultimateLayer], curLayer[indexInPenultimateLayer + 1], nextLayer[indexInUltimateLayer + 1], nextLayer[indexInUltimateLayer], curLayer[indexInPenultimateLayer] };
potential = potential.AddCycle(new DetachedCycle <int>(squareVertices), squareSign);
// Add pentagon
int pentagonSign = -squareSign;
indexInPenultimateLayer += 1;
indexInUltimateLayer += 1;
var pentagonVertices = pentagonSign == +1 ?
new int[] { curLayer[indexInPenultimateLayer + 1], curLayer[indexInPenultimateLayer], nextLayer[indexInUltimateLayer], nextLayer[indexInUltimateLayer + 1], nextLayer[indexInUltimateLayer + 2], curLayer[indexInPenultimateLayer + 1] } :
new int[] { curLayer[indexInPenultimateLayer], curLayer[indexInPenultimateLayer + 1], nextLayer[indexInUltimateLayer + 2], nextLayer[indexInUltimateLayer + 1], nextLayer[indexInUltimateLayer], curLayer[indexInPenultimateLayer] };
potential = potential.AddCycle(new DetachedCycle <int>(pentagonVertices), pentagonSign);
}
}
}
var qp = new QuiverWithPotential <int>(potential);
return(qp);
CircularList <int> GetLayerVertices(int layerIndex)
=> new CircularList <int>(GetVerticesInEvenFlowerType2QPLayer(numVerticesInCenterPolygon, layerIndex, firstVertex));
}
public static bool SquareParameterIsValid(int numRows) => UsefulQuivers.SquareParameterIsValid(numRows);
public static IEnumerable <int> GetVerticesInEvenFlowerType2QPLayer(int numVerticesInCenterPolygon, int layerIndex, int firstVertex = DefaultFirstVertex) => UsefulQuivers.GetVerticesInEvenFlowerType2QuiverLayer(numVerticesInCenterPolygon, layerIndex, firstVertex);