public static IFloatMatrix AU(IFloatMatrix A, IROFloatVector u, int r1, int r2, int c1, int c2, IFloatVector v)
{
if (r2 < r1 || c2 < c1)
{
return(A);
}
if (c2 - c1 + 1 > u.Length)
{
throw new ArgumentException("Householder vector too short.", "u");
}
if (r2 - r1 + 1 > v.Length)
{
throw new ArgumentException("Work vector too short.", "v");
}
for (int i = r1; i <= r2; i++)
{
v[i - r1] = 0.0f;
for (int j = c1; j <= c2; j++)
{
v[i - r1] = v[i - r1] + A[i, j] * u[j - c1];
}
}
for (int i = r1; i <= r2; i++)
{
for (int j = c1; j <= c2; j++)
{
A[i, j] = A[i, j] - v[i - r1] * u[j - c1];
}
}
return(A);
}
public static IFloatMatrix AU(IFloatMatrix A, IROFloatVector u, int r1, int r2, int c1, int c2)
{
if (r2 < r1)
{
return(A);
}
return(AU(A, u, r1, r2, c1, c2, new FloatVector(r2 - r1 + 1)));
}
public static IROFloatMatrix UA(IROFloatVector u, IFloatMatrix A, int r1, int r2, int c1, int c2)
{
if (c1 > c2)
{
return(A);
}
return(UA(u, A, r1, r2, c1, c2, new FloatVector(c2 - c1 + 1)));
}
public static FloatVector GenerateColumn(IFloatMatrix A, int r1, int r2, int c)
{
int ru = r2 - r1 + 1;
FloatVector u = new FloatVector(r2 - r1 + 1);
for (int i = r1; i <= r2; i++)
{
u[i - r1] = A[i, c];
A[i, c] = 0.0f;
}
float norm = u.GetNorm();
if (r1 == r2 || norm == 0)
{
A[r1, c] = -u[0];
u[0] = (float)System.Math.Sqrt(2);
return(u);
}
float scale = 1.0f / norm;
if (u[0] < 0.0f)
{
scale *= -1.0f;
}
A[r1, c] = -1.0f / scale;
for (int i = 0; i < ru; i++)
{
u[i] = u[i] * scale;
}
u[0] = u[0] + 1.0f;
float s = (float)System.Math.Sqrt(1 / u[0]);
for (int i = 0; i < ru; i++)
{
u[i] = s * u[i];
}
return(u);
}
public static FloatVector GenerateRow(IFloatMatrix A, int r, int c1, int c2)
{
int cu = c2 - c1 + 1;
FloatVector u = new FloatVector(cu);
for (int j = c1; j <= c2; j++)
{
u[j - c1] = A[r, j];
A[r, j] = 0.0f;
}
float norm = u.GetNorm();
if (c1 == c2 || norm == 0)
{
A[r, c1] = -u[0];
u[0] = (float)System.Math.Sqrt(2);
return(u);
}
float scale = 1.0f / norm;
if (u[0] < 0.0f)
{
scale *= -1.0f;
}
A[r, c1] = -1.0f / scale;
for (int j = 0; j < cu; j++)
{
u[j] *= scale;
}
u[0] += 1.0f;
float s = (float)System.Math.Sqrt(1 / u[0]);
for (int j = 0; j < cu; j++)
{
u[j] *= s;
}
return(u);
}
public static IFloatMatrix AU(IFloatMatrix A, IROFloatVector u, int r1, int r2, int c1, int c2)
{
if (r2 < r1)
{
return A;
}
return AU(A, u, r1, r2, c1, c2, new FloatVector(r2 - r1 + 1));
}
public static IFloatMatrix AU(IFloatMatrix A, IROFloatVector u, int r1, int r2, int c1, int c2, IFloatVector v)
{
if (r2 < r1 || c2 < c1)
{
return A;
}
if (c2 - c1 + 1 > u.Length)
{
throw new ArgumentException("Householder vector too short.", "u");
}
if (r2 - r1 + 1 > v.Length)
{
throw new ArgumentException("Work vector too short.", "v");
}
for (int i = r1; i <= r2; i++)
{
v[i - r1] = 0.0f;
for (int j = c1; j <= c2; j++)
{
v[i - r1] = v[i - r1] + A[i, j] * u[j - c1];
}
}
for (int i = r1; i <= r2; i++)
{
for (int j = c1; j <= c2; j++)
{
A[i, j] = A[i, j] - v[i - r1] * u[j - c1];
}
}
return A;
}
public static IROFloatMatrix UA(IROFloatVector u, IFloatMatrix A, int r1, int r2, int c1, int c2)
{
if (c1 > c2)
{
return A;
}
return UA(u, A, r1, r2, c1, c2, new FloatVector(c2 - c1 + 1));
}
public static FloatVector GenerateRow(IFloatMatrix A, int r, int c1, int c2)
{
int cu = c2 - c1 + 1;
FloatVector u = new FloatVector(cu);
for (int j = c1; j <= c2; j++)
{
u[j - c1] = A[r, j];
A[r, j] = 0.0f;
}
float norm = u.GetNorm();
if (c1 == c2 || norm == 0)
{
A[r, c1] = -u[0];
u[0] = (float)System.Math.Sqrt(2);
return u;
}
float scale = 1.0f / norm;
if (u[0] < 0.0f)
scale *= -1.0f;
A[r, c1] = -1.0f / scale;
for (int j = 0; j < cu; j++)
{
u[j] *= scale;
}
u[0] += 1.0f;
float s = (float)System.Math.Sqrt(1 / u[0]);
for (int j = 0; j < cu; j++)
{
u[j] *= s;
}
return u;
}
public static FloatVector GenerateColumn(IFloatMatrix A, int r1, int r2, int c)
{
int ru = r2 - r1 + 1;
FloatVector u = new FloatVector(r2 - r1 + 1);
for (int i = r1; i <= r2; i++)
{
u[i - r1] = A[i, c];
A[i, c] = 0.0f;
}
float norm = u.GetNorm();
if (r1 == r2 || norm == 0)
{
A[r1, c] = -u[0];
u[0] = (float)System.Math.Sqrt(2);
return u;
}
float scale = 1.0f / norm;
if (u[0] < 0.0f)
scale *= -1.0f;
A[r1, c] = -1.0f / scale;
for (int i = 0; i < ru; i++)
{
u[i] = u[i] * scale;
}
u[0] = u[0] + 1.0f;
float s = (float)System.Math.Sqrt(1 / u[0]);
for (int i = 0; i < ru; i++)
{
u[i] = s * u[i];
}
return u;
}
