##### https://github.com/Benny44/LADEL

Tip revision:

**22d4d4c1a1de53c86ed6b15fe34fdbe7d39011af**authored by**Pieter P**on**13 February 2022, 15:40:31 UTC****Update README to point to https://github.com/kul-optec/QPALM** Tip revision:

**22d4d4c** ladel_pattern.c

```
#include "ladel_types.h"
#include "ladel_constants.h"
#include "ladel_global.h"
ladel_int ladel_nonzero_pattern_of_row_in_L(ladel_sparse_matrix *M,
ladel_symbolics *sym,
ladel_int row)
{
ladel_int start = M->ncol, index, next_node, nb_marked_nodes;
ladel_int *etree = sym->etree, *pattern = sym->pattern, *nodes = sym->nodes;
MARK(nodes,row);
LADEL_FOR(index, M, row)
{
next_node = M->i[index];
nb_marked_nodes = 0;
/* mark all the nodes found by traversing the etree */
while (!IS_MARKED(nodes, next_node))
{
MARK(nodes, next_node);
pattern[nb_marked_nodes] = next_node;
nb_marked_nodes++;
next_node = etree[next_node];
}
/*append the newly marked nodes to pattern (which goes from ncol-1 to 0)*/
while (nb_marked_nodes > 0)
{
start--;
nb_marked_nodes--;
pattern[start] = pattern[nb_marked_nodes];
}
}
/* unmark all the nodes to prepare for finding the pattern of the next row */
for (index = start; index < M->ncol; index++) UNMARK(nodes, pattern[index]);
UNMARK(nodes, row);
return start;
}
ladel_int ladel_etree_dfs(ladel_sparse_matrix *W,
ladel_symbolics *sym,
ladel_int col_in_W,
ladel_int maximum_row)
{
ladel_int start = sym->ncol, index, next_node, nb_marked_nodes;
ladel_int *etree = sym->etree, *pattern = sym->pattern, *nodes = sym->nodes;
LADEL_FOR(index, W, col_in_W)
{
next_node = W->i[index];
if (next_node >= maximum_row) break;
nb_marked_nodes = 0;
/* mark all the nodes found by traversing the etree */
while (next_node != NONE && !IS_MARKED(nodes, next_node) && next_node < maximum_row)
{
MARK(nodes, next_node);
pattern[nb_marked_nodes] = next_node;
nb_marked_nodes++;
next_node = etree[next_node];
}
/*append the newly marked nodes to pattern (which goes from ncol-1 to 0)*/
while (nb_marked_nodes > 0)
{
start--;
nb_marked_nodes--;
pattern[start] = pattern[nb_marked_nodes];
}
}
/* unmark all the nodes to prepare for finding the pattern of the next row */
for (index = start; index < sym->ncol; index++) UNMARK(nodes, pattern[index]);
UNMARK(nodes, col_in_W);
return start;
}
```