public void mprove(VecDoub b, VecDoub x)
{
int i, j;
VecDoub r = new VecDoub(n);
for (i = 0; i < n; i++)
{
double sdp = -b[i];
for (j = 0; j < n; j++)
{
sdp += (double)aref[i][j] * (double)x[j];
}
r[i] = sdp;
}
solve(r, r);
for (i = 0; i < n; i++)
{
x[i] -= r[i];
}
}
public void solve(VecDoub b, VecDoub x)
{
int i, ii = 0, ip, j;
double sum;
if (b.size() != n || x.size() != n)
{
throw new Exception("LUdcmp::solve bad sizes");
}
for (i = 0; i < n; i++)
{
x[i] = b[i];
}
for (i = 0; i < n; i++)
{
ip = indx[i];
sum = x[ip];
x[ip] = x[i];
if (ii != 0)
{
for (j = ii - 1; j < i; j++)
{
sum -= lu[i][j] * x[j];
}
}
else if (sum != 0.0)
{
ii = i + 1;
}
x[i] = sum;
}
for (i = n - 1; i >= 0; i--)
{
sum = x[i];
for (j = i + 1; j < n; j++)
{
sum -= lu[i][j] * x[j];
}
x[i] = sum / lu[i][i];
}
}
public void solve(MatDoub b, MatDoub x)
{
int i, j, m = b.ncols();
if (b.nrows() != n || x.nrows() != n || b.ncols() != x.ncols())
{
throw new Exception("LUdcmp::solve bad sizes");
}
VecDoub xx = new VecDoub(n);
for (j = 0; j < m; j++)
{
for (i = 0; i < n; i++)
{
xx[i] = b[i][j];
}
solve(xx, xx);
for (i = 0; i < n; i++)
{
x[i][j] = xx[i];
}
}
}
public static void SWAP(VecDoub aVec, int a, VecDoub bVec, int b)
{
double dum = aVec[a]; aVec[a] = bVec[b]; bVec[b] = dum;
}
public LUdcmp(MatDoub a)
{
n = (a.nrows());
lu = (a);
aref = (a);
indx = new VecInt(n);
const double TINY = 1.0e-40;
int i, imax = int.MinValue, j, k;
double big, temp;
VecDoub vv = new VecDoub(n);
d = 1.0;
for (i = 0; i < n; i++)
{
big = 0.0;
for (j = 0; j < n; j++)
{
if ((temp = Math.Abs(lu[i][j])) > big)
{
big = temp;
}
}
if (big == 0.0)
{
throw new Exception("Singular matrix in LUdcmp");
}
vv[i] = 1.0 / big;
}
for (k = 0; k < n; k++)
{
big = 0.0;
for (i = k; i < n; i++)
{
temp = vv[i] * Math.Abs(lu[i][k]);
if (temp > big)
{
big = temp;
imax = i;
}
}
if (k != imax)
{
for (j = 0; j < n; j++)
{
temp = lu[imax][j];
lu[imax][j] = lu[k][j];
lu[k][j] = temp;
}
d = -d;
vv[imax] = vv[k];
}
indx[k] = imax;
if (lu[k][k] == 0.0)
{
lu[k][k] = TINY;
}
for (i = k + 1; i < n; i++)
{
temp = lu[i][k] /= lu[k][k];
for (j = k + 1; j < n; j++)
{
lu[i][j] -= temp * lu[k][j];
}
}
}
}
