Update approx. minimum ordering method to push and keep structural empty diagonal elements to the bottom-right part of the matrix

This commit is contained in:
Gael Guennebaud 2015-03-20 16:33:48 +01:00
parent 8d9bfb3a7b
commit 4e2b18d909

View File

@ -137,22 +137,27 @@ void minimum_degree_ordering(SparseMatrix<Scalar,ColMajor,StorageIndex>& C, Perm
degree[i] = len[i]; // degree of node i
}
mark = internal::cs_wclear<StorageIndex>(0, 0, w, n); /* clear w */
elen[n] = -2; /* n is a dead element */
Cp[n] = -1; /* n is a root of assembly tree */
w[n] = 0; /* n is a dead element */
/* --- Initialize degree lists ------------------------------------------ */
for(i = 0; i < n; i++)
{
bool has_diag = false;
for(p = Cp[i]; p<Cp[i+1]; ++p)
if(Ci[p]==i)
{
has_diag = true;
break;
}
d = degree[i];
if(d == 0) /* node i is empty */
if(d == 1) /* node i is empty */
{
elen[i] = -2; /* element i is dead */
nel++;
Cp[i] = -1; /* i is a root of assembly tree */
w[i] = 0;
}
else if(d > dense) /* node i is dense */
else if(d > dense || !has_diag) /* node i is dense or has no structural diagonal element */
{
nv[i] = 0; /* absorb i into element n */
elen[i] = -1; /* node i is dead */
@ -168,6 +173,10 @@ void minimum_degree_ordering(SparseMatrix<Scalar,ColMajor,StorageIndex>& C, Perm
}
}
elen[n] = -2; /* n is a dead element */
Cp[n] = -1; /* n is a root of assembly tree */
w[n] = 0; /* n is a dead element */
while (nel < n) /* while (selecting pivots) do */
{
/* --- Select node of minimum approximate degree -------------------- */