// find the cofactor matrix and return the same
public Matrix2D CoFactor()
{
int i1, j1;
double det;
Matrix2D m = new Matrix2D();
Matrix2D CMat = new Matrix2D();
for (var j = 0; j < 2; j++)
{
for (var i = 0; i < 2; i++)
{
i1 = 0;
for (var ii = 0; ii < 2; ii++)
{
if (ii != i)
{
j1 = 0;
for (var jj = 0; jj < 2; jj++)
{
if (jj != j)
{
m.matrix.SetValue(matrix[ii, jj], i1, j1);
j1 = +j1 + 1;
}
}
i1 = i1 + 1;
}
}
det = m.Determinant();
CMat.matrix.SetValue(System.Math.Pow(-1.0, i + j + 2.0) * det, i, j);
}
m = null;
}
return CMat;
}
// copy constructor
public Matrix2D(Matrix2D Mat)
{
this.matrix = new double[3, 3];
for (var i = matrix.GetLowerBound(0); i < matrix.GetUpperBound(0); i++)
{
for (var j = matrix.GetLowerBound(1); j < matrix.GetUpperBound(1); j++)
{
matrix.SetValue(Mat.matrix[i, j], i, j);
}
}
}
// multiply the currnet matrix with the parameter
public void PreMultiplyBy(Matrix2D Mat)
{
Matrix2D ThisMat = new Matrix2D();
Matrix2D CMat = new Matrix2D();
ThisMat.matrix = matrix;
CMat = Multiply(Mat, ThisMat);
matrix = CMat.matrix;
ThisMat = null;
CMat = null;
}
// multiply the currnet matrix with the parameter
public void PostMultiplyBY(Matrix2D Mat)
{
Matrix2D Thismat = new Matrix2D();
Matrix2D CMat = new Matrix2D();
Thismat.matrix = matrix;
CMat = Multiply(Thismat, Mat);
matrix = CMat.matrix;
Thismat = null;
CMat = null;
}
// multiply matrix 1 and 2 and return the resultant matrix
public Matrix2D Multiply(Matrix2D Mat1, Matrix2D Mat2)
{
Matrix2D Mat = new Matrix2D();
Double sum = 0;
for (var ii = 0; ii < 2; ii++)
{
for (var jj = 0; jj < 2; jj++)
{
sum = 0;
for (var kk = 0; kk < 2; kk++)
{
sum = sum + (Mat1.matrix[ii, kk] * Mat2.matrix[kk, jj]);
}
Mat.matrix.SetValue(sum, ii, jj);
}
}
return Mat;
}
// transform this point by the parameter matrix
public void TransformBy(Matrix2D Mat)
{
double xx = 0; double yy = 0;
xx = (X * Mat.matrix[0, 0]) + (Y * Mat.matrix[1, 0]) + (Mat.matrix[0, 2]);
yy = (X * Mat.matrix[0, 1]) + (Y * Mat.matrix[1, 1]) + (Mat.matrix[1, 2]);
X = xx;
Y = yy;
}