public static VectorR Transform(VectorR v, MatrixR m)
{
VectorR result = new VectorR(v.GetSize());
if (!m.IsSquared())
{
throw new ArgumentOutOfRangeException(
"Dimension", m.GetRows(), "The matrix must be squared!");
}
if (m.GetRows() != v.GetSize())
{
throw new ArgumentOutOfRangeException(
"Size", v.GetSize(), "The size of the vector must be equal"
+ "to the number of rows of the matrix!");
}
for (int i = 0; i < m.GetRows(); i++)
{
result[i] = 0.0;
for (int j = 0; j < m.GetCols(); j++)
{
result[i] += v[j] * m[j, i];
}
}
return(result);
}
public MatrixR ReplaceCol(VectorR v, int n)
{
if (n < 0 || n > Cols)
{
throw new ArgumentOutOfRangeException(
"n", n, "n is out of range!");
}
if (v.GetSize() != Rows)
{
throw new ArgumentOutOfRangeException(
"Vector size", v.GetSize(), "vector size is out of range!");
}
for (int i = 0; i < Rows; i++)
{
matrix[i, n] = v[i];
}
return(new MatrixR(matrix));
}
public static VectorR GaussJordan(MatrixR A, VectorR b)
{
Triangulate(A, b);
int n = b.GetSize();
VectorR x = new VectorR(n);
for (int i = n - 1; i >= 0; i--)
{
double d = A[i, i];
if (Math.Abs(d) < 1.0e-500)
{
throw new ArgumentException("Diagonal element is too small!");
}
x[i] = (b[i] - VectorR.DotProduct(A.GetRowVector(i), x)) / d;
}
return(x);
}
public static MatrixR Transform(VectorR v1, VectorR v2)
{
if (v1.GetSize() != v2.GetSize())
{
throw new ArgumentOutOfRangeException(
"v1", v1.GetSize(), "The vectors must have the same size!");
}
MatrixR result = new MatrixR(v1.GetSize(), v1.GetSize());
for (int i = 0; i < v1.GetSize(); i++)
{
for (int j = 0; j < v1.GetSize(); j++)
{
result[j, i] = v1[i] * v2[j];
}
}
return(result);
}
private static double Pivot(MatrixR A, VectorR b, int q)
{
int n = b.GetSize();
int i = q;
double d = 0.0;
for (int j = q; j < n; j++)
{
double dd = Math.Abs(A[j, q]);
if (dd > d)
{
d = dd;
i = j;
}
}
if (i > q)
{
A.GetRowSwap(q, i);
b.GetSwap(q, i);
}
return(A[q, q]);
}
