public Matrix Transform(CoordTransform newCoords, Matrix res = null, bool everyCycleOfLength2 = false)
{
if (res == this)
{
return(InPlaceTransform(newCoords, everyCycleOfLength2));
}
MakeOrValidate(newCoords.DimF(Rows, Cols), ref res);
for (int r = 0; r < Rows; r++)
{
for (int c = 0; c < Cols; c++)
{
res[newCoords.CoordF(this, r, c)] = this[r, c];
}
}
return(res);
}
// newCoords MUST permute the indices
public Matrix InPlaceTransform(CoordTransform newCoords, bool everyCycleOfLength2 = false)
{
ValidateDimensions(this, newCoords.DimF(Rows, Cols), "InPlaceTransform(CoordTransform newCoords, bool everyCycleOfLength2 = false)", "this");
if (!everyCycleOfLength2)
{
bool[,] completed = new bool[Rows, Cols]; // has to search through this. *HIGHLY* inefficient. FIX.
//double[] cycleV = new double[Rows * Cols];
Pair <int>[] cycleC = new Pair <int> [Rows * Cols];
int cycleBegin = 0;
int pos = 0;
cycleC[0] = new Pair <int>(0, 0);
while (pos < cycleC.Length)
{
Pair <int> nextCoords = newCoords.CoordF(this, cycleC[pos].x, cycleC[pos].y);
if (cycleC[cycleBegin].x == nextCoords.x && cycleC[cycleBegin].y == nextCoords.y)
{
// Cycle through
double temp1 = this[cycleC[pos]];
double temp2;
for (int i = cycleBegin; i <= pos; i++)
{
Pair <int> cs = cycleC[i];
temp2 = this[cs];
this[cs] = temp1;
temp1 = temp2;
completed[cs.x, cs.y] = true; // mark transformed
}
int r = 0, c = 0;
for (r = 0; r < Rows && completed[r, c]; r++)
{
for (c = 0; c < Cols && completed[r, c]; c++)
{
; // Loop through until we find something not completed
}
}
if (pos == cycleC.Length - 1)
{
break;
}
cycleBegin = pos++;
cycleC[cycleBegin] = new Pair <int>(r, c);
}
else
{
cycleC[++pos] = nextCoords;
}
}
}
else
{
bool[,] completed = new bool[Rows, Cols];
for (int r = 0; r < Rows; r++)
{
for (int c = 0; c < Cols; c++)
{
if (!completed[r, c])
{
Pair <int> otCoords = newCoords.CoordF(this, r, c);
double temp = this[otCoords];
this[otCoords] = this[r, c];
this[r, c] = temp;
completed[r, c] = true; // not strictly necessary, since we're about to move past it.
completed[otCoords.x, otCoords.y] = true;
}
}
}
}
return(this);
}