public static IntMatrix E(uint i, uint j, uint rowsAndCols)
{
var newM = new IntMatrix(rowsAndCols, rowsAndCols);
newM[i, j] = 1;
return(newM);
}
public IntMatrix MultiplyRow(uint r, int factor)
{
var newM = IntMatrix.FromArray(M);
for (uint c = 0; c < newM.Cols; c++)
{
newM[r, c] *= factor;
}
return(newM);
}
public IntMatrix AddRows(uint rSrc, uint rDst, int factor)
{
var newM = IntMatrix.FromArray(M);
for (uint c = 0; c < newM.Cols; c++)
{
newM[rDst, c] += factor * newM[rSrc, c];
}
return(newM);
}
public IntMatrix SwapRows(uint r1, uint r2)
{
var newM = IntMatrix.FromArray(M);
for (uint c = 0; c < newM.Cols; c++)
{
(newM[r1, c], newM[r2, c]) = (newM[r1, c], newM[r2, c]);
}
return(newM);
}
public static IntMatrix EinheitsMatrix(uint i)
{
var newM = new IntMatrix(i, i);
for (uint j = 0; j < i; j++)
{
newM[j, j] = 1;
}
return(newM);
}
public static IntMatrix FromArray(int[][] array)
{
var newM = new IntMatrix((uint)array.GetLength(0), (uint)array[0].GetLength(0));
for (int r = 0; r < array.GetLength(0); r++)
{
for (int c = 0; c < array.GetLength(1); c++)
{
newM.M[r, c] = array[r][c];
}
}
return(newM);
}
public static IntMatrix FromArray(int[] array, uint cols)
{
var newM = new IntMatrix((uint)array.GetLength(0) / cols, cols);
for (uint r = 0; r < array.GetLength(0); r++)
{
for (uint c = 0; c < array.GetLength(0); c++)
{
newM[r, c] = array[r * cols + r];
}
}
return(newM);
}
public static IntMatrix operator *(int factor, IntMatrix a)
{
IntMatrix newM = new IntMatrix(a.Rows, a.Cols);
for (uint r = 0; r < a.Rows; r++)
{
for (uint c = 0; c < a.Cols; c++)
{
newM.M[r, c] = a[r, c] * factor;
}
}
return(newM);
}
public static IntMatrix operator -(IntMatrix a, IntMatrix b)
{
if (a.Rows != b.Rows ||
a.Cols != b.Cols)
{
throw new System.NotSupportedException();
}
else
{
IntMatrix newM = new IntMatrix(a.Rows, a.Cols);
for (int r = 0; r < a.Cols; r++)
{
for (int c = 0; c < a.Cols; c++)
{
newM.M[r, c] = a.M[r, c] - b.M[r, c];
}
}
return(newM);
}
}
public static IntMatrix operator *(IntMatrix a, IntMatrix b)
{
if (a.Cols != b.Rows)
{
throw new System.NotSupportedException();
}
else
{
IntMatrix newM = new IntMatrix(a.Rows, b.Cols);
for (int r = 0; r < a.Rows; r++)
{
for (int c = 0; c < b.Cols; c++)
{
for (int x = 0; x < a.Cols; x++)
{
newM.M[r, c] += a.M[r, x] * b.M[x, c]; //
}
}
}
return(newM);
}
}
