private ChMelement NewElement(double mval, ChMelement mnext, ChMelement mprev, int mrow, int mcol)
{
if (mbuffer_added >= mbuffer_size)
{
MoreBuffer(2.0);
}
/*ChMelement[] newel = mnextel;
* mnextel.Initialize(mval, mnext, mprev, mrow, mcol);
* mbuffer_added++;
* mnextel++;*/
ChMelement newel = mnextel[mbuffer_added];
mnextel[mbuffer_added].Initialize(mval, mnext, mprev, mrow, mcol);
mbuffer_added++;
//ChMelement newel = new ChMelement();
/*ChMelement newel = mnextel;
* for (int i = 1; i < mnextel.Length; i++) {
*
* mnextel[i].Initialize(mval, mnext, mprev, mrow, mcol);
* mbuffer_added++;
* newel = mnextel[i + 1];
* //mnextel[i] = newel;
* }*/
return(newel);
}
public void Build(double fill_in)
{
mtot_size = 0;
mbuffer_added = 0;
mnextel = null;
// alloc buffer of elements
mbuffer_size = (int)(m_num_rows * m_num_cols * fill_in);
if (m_num_rows > 5000)
{
mbuffer_size = (int)ChSparseMatrix.SPM_DEF_MAXELEMENTS;
}
if (m_num_cols > 5000)
{
mbuffer_size = (int)ChSparseMatrix.SPM_DEF_MAXELEMENTS;
}
if (mbuffer_size > (int)ChSparseMatrix.SPM_DEF_MAXELEMENTS)
{
mbuffer_size = (int)ChSparseMatrix.SPM_DEF_MAXELEMENTS;
}
if (mbuffer_size < m_num_rows * 2)
{
mbuffer_size = m_num_rows * 2;
}
//var mbuffer = (ChMelement*)Marshal.AllocHGlobal(mbuffer_size *sizeof(ChMelement));
ChMelement[] mbuffer = new ChMelement[mbuffer_size];
for (int i = 0; i < mbuffer.Length; i++)
{
mbuffer[i] = new ChMelement();
}
mtot_size += mbuffer_size;
mnextel = mbuffer;
mbufferlist.AddHead(mbuffer);
// alloc pointers to first column
//elarray = (ChMelement[])calloc(m_num_rows, sizeof(ChMelement*));
//IntPtr array = Marshal.AllocHGlobal(m_num_rows);
//Marshal.FreeHGlobal(array);
//ChMelement** array = stackalloc ChMelement*[m_num_rows];
//elarray = (ChMelement**)Marshal.AllocHGlobal(m_num_rows * sizeof(ChMelement));
elarray = new ChMelement[m_num_rows];
for (int i = 0; i < elarray.Length; i++)
{
elarray[i] = new ChMelement();
}
for (int i = 0; i < m_num_rows; i++)
{
ChMelement pointer = mnextel[i];
(elarray[i]) = pointer; // initialize vector of 1st col pointr pointers
(mnextel[i]).Initialize(0, null, null, i, 0); // initialize 1st col.elements
mbuffer_added++; // increment the counter of "used" elements.
//mnextel++;
pointer = mnextel[i + 1];
}
}
public void Initialize(double mval, ChMelement mnext, ChMelement mprev, int mrow, int mcol)
{
val = mval;
next = mnext;
prev = mprev;
col = mcol;
row = mrow;
}
public ChMelement(double mval, ChMelement mnext, ChMelement mprev, int mrow, int mcol)
{
this.val = mval;
this.next = mnext;
this.prev = mprev;
this.row = mrow;
this.col = mcol;
}
// Substitution using existing LU factorization
public void Solve_LU(ChMatrix b, ref ChMatrix x)
{
//Debug.Assert(m_num_rows == b.GetRows());
//Debug.Assert(m_num_cols == x.GetRows());
// BACKWARD substitution - L
double xlast = b.GetElement(m_pindices[0], 0);
x.SetElement(0, 0, xlast);
for (int k = 1; k < m_num_rows; k++)
{
double sum = 0;
ChMelement rowel = GetElarrayMel(k);
for (; (rowel != null && rowel.col < k); rowel = rowel.next)
{
sum += rowel.val * (x.GetElement(rowel.col, 0));
}
double val = (b.GetElement(m_pindices[k], 0) - sum);
x.SetElement(k, 0, val);
}
// BACKWARD substitution - U
xlast = x.GetElement(m_num_rows - 1, 0) / GetElement(m_num_rows - 1, m_num_rows - 1);
x.SetElement(m_num_rows - 1, 0, xlast);
for (int k = m_num_rows - 2; k >= 0; k--)
{
double sum = 0;
ChMelement rowel = GetElarrayMel(k);
for (; rowel != null; rowel = rowel.next)
{
if (rowel.col >= k + 1)
{
sum += rowel.val * (x.GetElement(rowel.col, 0));
}
}
double val = (x.GetElement(k, 0) - sum) / GetElement(k, k);
x.SetElement(k, 0, val);
}
}
/// Add another buffer in buffer list, bigger of last
/// (max total buffer size = col x rows) as in newbuffer = lastbuffer * inflate
/// (use inflate >1, suggested 2) [mostly used internally]
public void MoreBuffer(double inflate)
{
mbuffer_size = (int)(inflate * (double)mbuffer_size); // inflate buffer size
if (m_num_rows < 5000)
{
if ((mtot_size + mbuffer_size) > m_num_rows * m_num_cols)
{
mbuffer_size = m_num_rows * m_num_cols - mtot_size;
}
}
ChMelement[] mbuffer = new ChMelement[mbuffer_size];
for (int i = 0; i < mbuffer.Length; i++)
{
mbuffer[i] = new ChMelement();
}
mtot_size += mbuffer_size;
mnextel = mbuffer;
mbufferlist.AddTail(mbuffer); // add another buffer!
mbuffer_added = 0;
}
/// Optimized GetElement, returning the fetched Melement*
public ChMelement GetElement(int row, int col, ref double val, ChMelement guess)
{
/*Debug.Assert(row >= 0);
* Debug.Assert(col >= 0);
* Debug.Assert(row < m_num_rows);
* Debug.Assert(col < m_num_cols);
* Debug.Assert(guess.row == row);*/
ChMelement enext;
ChMelement eprev;
while (guess.col != col)
{
// forward search
if (guess.col < col)
{
enext = guess.next;
if (enext != null)
{
if (enext.col <= col)
{
guess = enext; // .. and repeat
}
else // if (enext.col > col)
{
val = 0;
return(guess);
}
}
else
{
val = 0;
return(guess);
}
}
// backward search
if (guess.col > col)
{
eprev = guess.prev;
if (eprev != null)
{
if (eprev.col >= col)
{
guess = eprev; // .. and repeat
}
else // if (eprev.col < col)
{
val = 0;
return(guess);
}
}
else
{
val = 0;
return(guess);
}
}
} // end while loop
val = guess.val;
return(guess);
}
/// Optimized SetElement, returning the fetched Melement*
public ChMelement SetElement(int row, int col, double val, ChMelement guess)
{
/*Debug.Assert(row >= 0);
* Debug.Assert(col >= 0);
* Debug.Assert(row < m_num_rows);
* Debug.Assert(col < m_num_cols);
* Debug.Assert(guess.row == row);*/
ChMelement enext;
ChMelement eprev;
ChMelement newguess;
while (guess.col != col)
{
// forward search
if (guess.col < col)
{
enext = guess.next;
if (enext != null)
{
if (enext.col <= col)
{
guess = enext; // .. and repeat
}
else // if (enext.col > col)
{
newguess = NewElement(val, enext, guess, row, col);
guess.next = newguess;
enext.prev = newguess;
return(newguess);
}
}
else
{
newguess = NewElement(val, null, guess, row, col); // this one! bast!
guess.next = newguess;
return(newguess);
}
}
// backward search
if (guess.col > col)
{
eprev = guess.prev;
if (eprev != null)
{
if (eprev.col >= col)
{
guess = eprev; // .. and repeat
}
else // if (eprev.col < col)
{
newguess = NewElement(val, guess, eprev, row, col);
eprev.next = newguess;
guess.prev = newguess;
return(newguess);
}
}
else
{
newguess = NewElement(val, guess, null, row, col);
guess.prev = newguess;
return(newguess);
}
}
}
guess.val = val;
return(guess);
}
