1Graph::BitMatrix(3)   User Contributed Perl Documentation  Graph::BitMatrix(3)
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NAME

6       Graph::BitMatrix - create and manipulate a V x V bit matrix of graph G
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SYNOPSIS

9           use Graph::BitMatrix;
10           use Graph::Directed;
11           my $g  = Graph::Directed->new;
12           $g->add_...(); # build $g
13           my $m = Graph::BitMatrix->new($g, %opt);
14           $m->get($u, $v)
15           $m->set($u, $v)
16           $m->unset($u, $v)
17           $m->get_row($u, $v1, $v2, ..., $vn)
18           $m->set_row($u, $v1, $v2, ..., $vn)
19           $m->unset_row($u, $v1, $v2, ..., $vn)
20           $a->vertices()
21

DESCRIPTION

23       This class enables creating bit matrices that compactly describe the
24       connected of the graphs.
25
26   Class Methods
27       new($g)
28           Create a bit matrix from a Graph $g.  The %opt, if present, can
29           have the following options:
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31           •       connect_edges
32
33                   If true or if not present, set the bits in the bit matrix
34                   that correspond to edges.  If false, do not set any bits.
35                   In either case the bit matrix of V x V bits is allocated.
36
37           •       transpose
38
39                   If true, set the bits in the bit matrix that correspond to
40                   edges but in the reverse direction. This has the effect of
41                   transposing the matrix. Obviously makes no difference to
42                   the result for undirected graphs.
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44   Object Methods
45       get($u, $v)
46           Return true if the bit matrix has a "one bit" between the vertices
47           $u and $v; in other words, if there is (at least one) a vertex
48           going from $u to $v.  If there is no vertex and therefore a "zero
49           bit", return false.
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51       set($u, $v)
52           Set the bit between the vertices $u and $v; in other words, connect
53           the vertices $u and $v by an edge.  The change does not get
54           mirrored back to the original graph.  Returns nothing.
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56       unset($u, $v)
57           Unset the bit between the vertices $u and $v; in other words,
58           disconnect the vertices $u and $v by an edge.  The change does not
59           get mirrored back to the original graph.  Returns nothing.
60
61       get_row($u, $v1, $v2, ..., $vn)
62           Test the row at vertex "u" for the vertices "v1", "v2", ..., "vn"
63           Returns a list of n truth values.
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65       set_row($u, $v1, $v2, ..., $vn)
66           Sets the row at vertex "u" for the vertices "v1", "v2", ..., "vn",
67           in other words, connects the vertex "u" to the vertices "vi".  The
68           changes do not get mirrored back to the original graph.  Returns
69           nothing.
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71       unset_row($u, $v1, $v2, ..., $vn)
72           Unsets the row at vertex "u" for the vertices "v1", "v2", ...,
73           "vn", in other words, disconnects the vertex "u" from the vertices
74           "vi".  The changes do not get mirrored back to the original graph.
75           Returns nothing.
76
77       vertices
78           Return the list of vertices in the bit matrix.
79

ALGORITHM

81       The algorithm used to create the matrix is two nested loops, which is
82       O(V**2) in time, and the returned matrices are O(V**2) in space.
83

85       Jarkko Hietaniemi jhi@iki.fi
86

LICENSE

88       This module is licensed under the same terms as Perl itself.
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92perl v5.36.0                      2022-07-22               Graph::BitMatrix(3)
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