NAME¶
Graph::BitMatrix - create and manipulate a V x V bit matrix of graph G
SYNOPSIS¶
use Graph::BitMatrix;
use Graph::Directed;
my $g = Graph::Directed->new;
$g->add_...(); # build $g
my $m = Graph::BitMatrix->new($g, %opt);
$m->get($u, $v)
$m->set($u, $v)
$m->unset($u, $v)
$m->get_row($u, $v1, $v2, ..., $vn)
$m->set_row($u, $v1, $v2, ..., $vn)
$m->unset_row($u, $v1, $v2, ..., $vn)
$a->vertices()
DESCRIPTION¶
This class enables creating bit matrices that compactly describe the connected
of the graphs.
Class Methods¶
- new($g)
- Create a bit matrix from a Graph $g. The %opt, if present, can have the
following options:
- •
- connect_edges
If true or if not present, set the bits in the bit matrix that correspond to
edges. If false, do not set any bits. In either case the bit matrix of V x
V bits is allocated.
Object Methods¶
- get($u, $v)
- Return true if the bit matrix has a "one bit" between the
vertices $u and $v; in other words, if there is (at least one) a vertex
going from $u to $v. If there is no vertex and therefore a "zero
bit", return false.
- set($u, $v)
- Set the bit between the vertices $u and $v; in other words, connect the
vertices $u and $v by an edge. The change does not get mirrored back to
the original graph. Returns nothing.
- unset($u, $v)
- Unset the bit between the vertices $u and $v; in other words, disconnect
the vertices $u and $v by an edge. The change does not get mirrored back
to the original graph. Returns nothing.
- get_row($u, $v1, $v2, ..., $vn)
- Test the row at vertex "u" for the vertices "v1",
"v2", ..., "vn" Returns a list of n truth
values.
- set_row($u, $v1, $v2, ..., $vn)
- Sets the row at vertex "u" for the vertices "v1",
"v2", ..., "vn", in other words, connects the vertex
"u" to the vertices "vi". The changes do not get
mirrored back to the original graph. Returns nothing.
- unset_row($u, $v1, $v2, ..., $vn)
- Unsets the row at vertex "u" for the vertices "v1",
"v2", ..., "vn", in other words, disconnects the
vertex "u" from the vertices "vi". The changes do not
get mirrored back to the original graph. Returns nothing.
- vertices
- Return the list of vertices in the bit matrix.
ALGORITHM¶
The algorithm used to create the matrix is two nested loops, which is O(V**2) in
time, and the returned matrices are O(V**2) in space.
AUTHOR AND COPYRIGHT¶
Jarkko Hietaniemi
jhi@iki.fi
LICENSE¶
This module is licensed under the same terms as Perl itself.