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Desire NUENTSA
2012-06-13 18:26:05 +02:00
parent c0ad109499
commit f8a0745cb0
22 changed files with 559 additions and 548 deletions
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97
Eigen/src/SparseLU/SparseLU_Coletree.h
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@@ -44,13 +44,28 @@
*/
#ifndef SPARSELU_COLETREE_H
#define SPARSELU_COLETREE_H
/** Find the root of the tree/set containing the vertex i : Use Path halving */
template<typename IndexVector>
int etree_find (int i, IndexVector& pp)
{
int p = pp(i); // Parent
int gp = pp(p); // Grand parent
while (gp != p)
{
pp(i) = gp; // Parent pointer on find path is changed to former grand parent
i = gp;
p = pp(i);
gp = pp(p);
}
return p;
}
/** Compute the column elimination tree of a sparse matrix
* NOTE : The matrix is supposed to be in column-major format.
*
*/
template<typename MatrixType, typename IndexVector>
int SparseLU::LU_sp_coletree(const MatrixType& mat, IndexVector& parent)
int LU_sp_coletree(const MatrixType& mat, IndexVector& parent)
{
int nc = mat.cols(); // Number of columns
int nr = mat.rows(); // Number of rows
@@ -87,7 +102,7 @@ int SparseLU::LU_sp_coletree(const MatrixType& mat, IndexVector& parent)
{ // A sequence of interleaved find and union is performed
row = firstcol(it.row());
if (row >= col) continue;
rset = internal::etree_find(row, pp); // Find the name of the set containing row
rset = etree_find(row, pp); // Find the name of the set containing row
rroot = root(rset);
if (rroot != col)
{
@@ -100,52 +115,6 @@ int SparseLU::LU_sp_coletree(const MatrixType& mat, IndexVector& parent)
return 0;
}
/** Find the root of the tree/set containing the vertex i : Use Path halving */
template<typename IndexVector>
int etree_find (int i, IndexVector& pp)
{
int p = pp(i); // Parent
int gp = pp(p); // Grand parent
while (gp != p)
{
pp(i) = gp; // Parent pointer on find path is changed to former grand parent
i = gp;
p = pp(i);
gp = pp(p);
}
return p;
}
/**
* Post order a tree
* \param parent Input tree
* \param post postordered tree
*/
template<typename IndexVector>
void SparseLU::LU_TreePostorder(int n, IndexVector& parent, IndexVector& post)
{
IndexVector first_kid, next_kid; // Linked list of children
int postnum;
// Allocate storage for working arrays and results
first_kid.resize(n+1);
next_kid.setZero(n+1);
post.setZero(n+1);
// Set up structure describing children
int v, dad;
first_kid.setConstant(-1);
for (v = n-1, v >= 0; v--)
{
dad = parent(v);
next_kid(v) = first_kid(dad);
first_kid(dad) = v;
}
// Depth-first search from dummy root vertex #n
postnum = 0;
internal::LU_nr_etdfs(n, parent, first_kid, next_kid, post, postnum);
return post;
}
/**
* Depth-first search from vertex n. No recursion.
* This routine was contributed by Cédric Doucet, CEDRAT Group, Meylan, France.
@@ -190,4 +159,36 @@ void LU_nr_etdfs (int n, IndexVector& parent, IndexVector& first_kid, IndexVecto
}
}
/**
* Post order a tree
* \param parent Input tree
* \param post postordered tree
*/
template<typename IndexVector>
void LU_TreePostorder(int n, IndexVector& parent, IndexVector& post)
{
IndexVector first_kid, next_kid; // Linked list of children
int postnum;
// Allocate storage for working arrays and results
first_kid.resize(n+1);
next_kid.setZero(n+1);
post.setZero(n+1);
// Set up structure describing children
int v, dad;
first_kid.setConstant(-1);
for (v = n-1; v >= 0; v--)
{
dad = parent(v);
next_kid(v) = first_kid(dad);
first_kid(dad) = v;
}
// Depth-first search from dummy root vertex #n
postnum = 0;
LU_nr_etdfs(n, parent, first_kid, next_kid, post, postnum);
return post;
}
#endif