# graph-motifs

From igraph v0.7.1
by Gabor Csardi

##### Graph motifs

Graph motifs are small connected subgraphs with a well-defined structure. These functions search a graph for various motifs.

- Keywords
- graphs

##### Usage

```
graph.motifs(graph, size = 3, cut.prob = rep(0, size))
graph.motifs.no(graph, size = 3, cut.prob = rep(0, size))
graph.motifs.est(graph, size = 3, cut.prob = rep(0, size), sample.size =
vcount(graph)/10, sample = NULL)
```

##### Arguments

- graph
- Graph object, the input graph.
- size
- The size of the motif, currently 3 and 4 are supported only.
- cut.prob
- Numeric vector giving the probabilities that the
search graph is cut at a certain level. Its length should be the
same as the size of the motif (the
`size`

argument). By default no cuts are made. - sample.size
- The number of vertices to use as a starting point
for finding motifs. Only used if the
`sample`

argument is`NULL`

. - sample
- If not
`NULL`

then it specifies the vertices to use as a starting point for finding motifs.

##### Details

`graph.motifs`

searches a graph for motifs of a given size and
returns a numeric vector containing the number of different
motifs. The order of the motifs is defined by their isomorphism class,
see `graph.isoclass`

.

`graph.motifs.no`

calculates the total number of motifs of a
given size in graph.

`graph.motifs.est`

estimates the total number of motifs of a
given size in a graph based on a sample.

##### Value

`graph.motifs`

returns a numeric vector, the number of occurences of each motif in the graph. The motifs are ordered by their isomorphism classes. Note that for unconnected subgraphs, which are not considered to be motifs, the result will be`NA`

.`graph.motifs.no`

and`graph.motifs.est`

return a numeric constant.

##### concept

Graph motif

##### See Also

##### Examples

```
g <- barabasi.game(100)
graph.motifs(g, 3)
graph.motifs.no(g, 3)
graph.motifs.est(g, 3)
```

*Documentation reproduced from package igraph, version 0.7.1, License: GPL (>= 2)*

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