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