1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
|
.TH graph_2_mat 1 "September 1995" "Scilab Group" "Scilab function"
.so ../sci.an
.SH NAME
graph_2_mat - node-arc or node-node incidence matrix of a graph
.SH CALLING SEQUENCE
.nf
a = graph_2_mat(g,mat)
.fi
.SH PARAMETERS
.TP 2
g
: graph list
.TP 4
mat
: optional string, 'node-arc' or 'node-node' matrix
.TP 2
a
: sparse node-arc or node-node incidence matrix
.SH DESCRIPTION
\fVgraph_2_mat\fR computes the node-arc or the node-node incidence matrix
corresponding
to the graph \fVg\fR.
If the optional argument \fVmat\fR is omitted or is the string
\fV'node-arc'\fR, the node-arc matrix is computed. If \fVmat\fR is the string
\fV'node-node'\fR, the node-node matrix is computed.
If \fVn\fR is the number of nodes of the graph and
\fVm\fR is the number of edges of the graph, the node-arc matrix is a Scilab
sparse matrix of size \fV(n,m)\fR.
It is defined as follows. If the graph is directed:
\fVa(i,j) = +1\fR if node \fVi\fR is the tail of arc \fVj\fR
\fVa(i,j) = -1\fR if node \fVi\fR is the head of arc \fVj\fR
If the graph is undirected:
\fVa(i,j) = 1\fR if node \fVi\fR is the tail or the head of arc \fVj\fR
If \fVn\fR is the number of nodes of the graph, the node-node matrix is a
Scilab sparse matrix of size \fV(n,n)\fR.
It is defined as follows:
\fVa(i,j) = 1\fR if there is an arc from node \fVi\fR to node \fVj\fR
.SH EXAMPLE
.nf
g=load_graph(SCI+'/demos/metanet/colored');
a=graph_2_mat(g)
a=graph_2_mat(g,'node-node')
.fi
.SH SEE ALSO
mat_2_graph
|
