Cheatography

# iGraph Cheat Sheet by trvoldemort

iGraph Commands

### Gaining inform­ation about graph structure

 `vcount(g)` count the number of vertices `ecount(g)` count the number of edges `neighb­ors­(g,v)` list the neighbors of a vertex `incide­nt(g,v)` list the incident edges of a vertex `is.dir­ect­ed(g)` determine whether the graph is directed `are.co­nne­cte­d(g­,v1,v2)` determine whether there is an edge between two vertices `get.ed­ge(­g,id)` get endpoints of an edge `get.ed­ges­(g,es)` get endpoints of a list of edges

### Graph, vertex and edge attributes

 In the following functions, `?` can be `graph`, `vertex` or `edge`. `get.?.a­tt­rib­ute­(g,n)` `set.?.a­tt­rib­ute­(g,n,v)` `list.?.at­tri­but­es(g)` `?.attr­ibu­tes(g)` `remove.?.a­tt­rib­ute­(g,n)`

### Various methods for creating graphs

 `graph.e­mpty()` `graph.s­tar(n)` `graph.l­at­tic­e(c­(n,m))` `graph.r­ing(n)` `graph.t­ree(n)` `graph.f­ull(n)` `graph.f­ul­l.c­ita­tion(n)` `graph.a­tl­as(­0-1252)` `graph(­c(1­,2,­2,3­,3,­4,...))` `graph.e­dg­eli­st(­edg­e.m­atrix)` `graph.f­or­mul­a(1­-2,­3,4-+5)`

### Vertex and edge sequences and iterators

 `V(g)` list vertices in a `igraph.vs` object `V(g)\$n­umber` get or set vertices properties `V(g)[n­umb­er<50]` get a subset of vertices `E(g)` list edges in a `igraph.es` object

### Method for structural manipu­lation of graphs

 `g[]` get and set adjacency matrix `g[[]]` get adjacency list

### Degree and degree distri­bution of the vertices

 `degree(g)` `degree.di­str­ibu­tion(g)`

### Graph Algebra

 `graph.u­ni­on(­g1,g2)` `graph.d­if­fer­enc­e(g­1,g2)`

### Print Graph

 `summary(g)` summary `str(g)` summary with edge list `print(g)` custom­izable printing function

### Neighb­orhood of graph vertices

 `neighb­orh­ood.si­ze(g,o)` gives a list of neighb­orhood size for each vertex `neighb­orh­ood­(g,o)` gives a list of neighb­orhood vertices for each vertex `graph.n­ei­ghb­orh­ood­(g,o)` gives the neighb­orhood graphs `connec­t.n­eig­hbo­rho­od(g,o)` creates a new graph by connect each vertex with its neighbor vertices

good cheat sheet