# Network Analysis and Visualization

## Documentation for package ‘igraph’ version 1.3.5

- DESCRIPTION file.
- Code demos. Use demo() to run them.
- Package NEWS.

## Help Pages

A B C D E F G H I K L M N O P Q R S T U V W misc

igraph-package | The igraph package

## -- A --

add.edges | Add edges to a graph
add.vertex.shape | Various vertex shapes when plotting igraph graphs
add.vertices | Add vertices to a graph
add_edges | Add edges to a graph
add_layout_ | Add layout to graph
add_shape | Various vertex shapes when plotting igraph graphs
add_vertices | Add vertices to a graph
adhesion | Edge connectivity.
adjacent.triangles | Find triangles in graphs
adjacent_vertices | Adjacent vertices of multiple vertices in a graph
aging.ba.game | Generate an evolving random graph with preferential attachment and aging
aging.barabasi.game | Generate an evolving random graph with preferential attachment and aging
aging.prefatt.game | Generate an evolving random graph with preferential attachment and aging
algorithm | Functions to deal with the result of network community detection
all_shortest_paths | Shortest (directed or undirected) paths between vertices
all_simple_paths | List all simple paths from one source
alpha.centrality | Find Bonacich alpha centrality scores of network positions
alpha_centrality | Find Bonacich alpha centrality scores of network positions
any_loop | Find the multiple or loop edges in a graph
any_multiple | Find the multiple or loop edges in a graph
are.connected | Are two vertices adjacent?
are_adjacent | Are two vertices adjacent?
arpack | ARPACK eigenvector calculation
arpack-options | ARPACK eigenvector calculation
arpack.unpack.complex | ARPACK eigenvector calculation
arpack_defaults | ARPACK eigenvector calculation
articulation.points | Articulation points and bridges of a graph
articulation_points | Articulation points and bridges of a graph
as.dendrogram.communities | Functions to deal with the result of network community detection
as.directed | Convert between directed and undirected graphs
as.hclust.communities | Functions to deal with the result of network community detection
as.igraph | Conversion to igraph
as.igraph.igraphHRG | Conversion to igraph
as.matrix.igraph | Convert igraph objects to adjacency or edge list matrices
as.undirected | Convert between directed and undirected graphs
asPhylo | Functions to deal with the result of network community detection
asPhylo.communities | Functions to deal with the result of network community detection
assortativity | Assortativity coefficient
assortativity.degree | Assortativity coefficient
assortativity.nominal | Assortativity coefficient
assortativity_degree | Assortativity coefficient
assortativity_nominal | Assortativity coefficient
asymmetric.preference.game | Trait-based random generation
asym_pref | Trait-based random generation
as_adj | Convert a graph to an adjacency matrix
as_adjacency_matrix | Convert a graph to an adjacency matrix
as_adj_edge_list | Adjacency lists
as_adj_list | Adjacency lists
as_bipartite | Simple two-row layout for bipartite graphs
as_data_frame | Creating igraph graphs from data frames or vice-versa
as_edgelist | Convert a graph to an edge list
as_graphnel | Convert igraph graphs to graphNEL objects from the graph package
as_ids | Convert a vertex or edge sequence to an ordinary vector
as_ids.igraph.es | Convert a vertex or edge sequence to an ordinary vector
as_ids.igraph.vs | Convert a vertex or edge sequence to an ordinary vector
as_incidence_matrix | Incidence matrix of a bipartite graph
as_long_data_frame | Convert a graph to a long data frame
as_membership | Declare a numeric vector as a membership vector
as_phylo | Functions to deal with the result of network community detection
as_phylo.communities | Functions to deal with the result of network community detection
as_star | Generate coordinates to place the vertices of a graph in a star-shape
as_tree | The Reingold-Tilford graph layout algorithm
atlas | Create a graph from the Graph Atlas
attribute.combination | How igraph functions handle attributes when the graph changes
attributes | List names of graph attributes
authority.score | Kleinberg's authority centrality scores.
authority_score | Kleinberg's authority centrality scores.
autocurve.edges | Optimal edge curvature when plotting graphs
automorphisms | Number of automorphisms
automorphism_group | Generating set of the automorphism group of a graph
average.path.length | Shortest (directed or undirected) paths between vertices
average_local_efficiency | Efficiency of a graph

## -- B --

ba.game | Generate random graphs using preferential attachment
barabasi.game | Generate random graphs using preferential attachment
betweenness | Vertex and edge betweenness centrality
betweenness.estimate | Vertex and edge betweenness centrality
bfs | Breadth-first search
bibcoupling | Cocitation coupling
biconnected.components | Biconnected components
biconnected_components | Biconnected components
bipartite | Bipartite random graphs
bipartite.mapping | Decide whether a graph is bipartite
bipartite.projection | Project a bipartite graph
bipartite.projection.size | Project a bipartite graph
bipartite.random.game | Bipartite random graphs
bipartite_graph | Create a bipartite graph
bipartite_mapping | Decide whether a graph is bipartite
bipartite_projection | Project a bipartite graph
bipartite_projection_size | Project a bipartite graph
blockGraphs | Calculate Cohesive Blocks
blocks | Calculate Cohesive Blocks
bonpow | Find Bonacich Power Centrality Scores of Network Positions
bridges | Articulation points and bridges of a graph

## -- C --

c.igraph.es | Concatenate edge sequences
c.igraph.vs | Concatenate vertex sequences
callaway.traits.game | Graph generation based on different vertex types
canonical.permutation | Canonical permutation of a graph
canonical_permutation | Canonical permutation of a graph
categorical_pal | Palette for categories
centralization | Centralization of a graph
centralization.betweenness | Centralize a graph according to the betweenness of vertices
centralization.betweenness.tmax | Theoretical maximum for betweenness centralization
centralization.closeness | Centralize a graph according to the closeness of vertices
centralization.closeness.tmax | Theoretical maximum for closeness centralization
centralization.degree | Centralize a graph according to the degrees of vertices
centralization.degree.tmax | Theoretical maximum for degree centralization
centralization.evcent | Centralize a graph according to the eigenvector centrality of vertices
centralization.evcent.tmax | Theoretical maximum for betweenness centralization
centralize | Centralization of a graph
centralize.scores | Centralization of a graph
centr_betw | Centralize a graph according to the betweenness of vertices
centr_betw_tmax | Theoretical maximum for betweenness centralization
centr_clo | Centralize a graph according to the closeness of vertices
centr_clo_tmax | Theoretical maximum for closeness centralization
centr_degree | Centralize a graph according to the degrees of vertices
centr_degree_tmax | Theoretical maximum for degree centralization
centr_eigen | Centralize a graph according to the eigenvector centrality of vertices
centr_eigen_tmax | Theoretical maximum for betweenness centralization
chordal_ring | Create an extended chordal ring graph
cited.type.game | Random citation graphs
citing.cited.type.game | Random citation graphs
cit_cit_types | Random citation graphs
cit_types | Random citation graphs
clique.number | Functions to find cliques, ie. complete subgraphs in a graph
cliques | Functions to find cliques, ie. complete subgraphs in a graph
clique_num | Functions to find cliques, ie. complete subgraphs in a graph
clique_size_counts | Functions to find cliques, ie. complete subgraphs in a graph
closeness | Closeness centrality of vertices
closeness.estimate | Closeness centrality of vertices
cluster.distribution | Connected components of a graph
clusters | Connected components of a graph
cluster_edge_betweenness | Community structure detection based on edge betweenness
cluster_fast_greedy | Community structure via greedy optimization of modularity
cluster_fluid_communities | Community detection algorithm based on interacting fluids
cluster_infomap | Infomap community finding
cluster_label_prop | Finding communities based on propagating labels
cluster_leading_eigen | Community structure detecting based on the leading eigenvector of the community matrix
cluster_leiden | Finding community structure of a graph using the Leiden algorithm of Traag, van Eck & Waltman.
cluster_louvain | Finding community structure by multi-level optimization of modularity
cluster_optimal | Optimal community structure
cluster_spinglass | Finding communities in graphs based on statistical meachanics
cluster_walktrap | Community structure via short random walks
cocitation | Cocitation coupling
code.length | Functions to deal with the result of network community detection
code_len | Functions to deal with the result of network community detection
cohesion | Vertex connectivity.
cohesion.cohesiveBlocks | Calculate Cohesive Blocks
cohesion.igraph | Vertex connectivity.
cohesive.blocks | Calculate Cohesive Blocks
cohesiveBlocks | Calculate Cohesive Blocks
cohesive_blocks | Calculate Cohesive Blocks
communities | Functions to deal with the result of network community detection
compare | Compares community structures using various metrics
compare.communities | Compares community structures using various metrics
compare.membership | Compares community structures using various metrics
complementer | Complementer of a graph
components | Connected components of a graph
component_distribution | Connected components of a graph
component_wise | Component-wise layout
compose | Compose two graphs as binary relations
connect | Neighborhood of graph vertices
connect.neighborhood | Neighborhood of graph vertices
consensus_tree | Create a consensus tree from several hierarchical random graph models
console | The igraph console
constraint | Burt's constraint
contract | Contract several vertices into a single one
contract.vertices | Contract several vertices into a single one
convex.hull | Convex hull of a set of vertices
convex_hull | Convex hull of a set of vertices
coreness | K-core decomposition of graphs
count.multiple | Find the multiple or loop edges in a graph
count_components | Connected components of a graph
count_isomorphisms | Count the number of isomorphic mappings between two graphs
count_max_cliques | Functions to find cliques, ie. complete subgraphs in a graph
count_max_weighted_cliques | Functions to find weighted cliques, ie. weighted complete subgraphs in a graph
count_motifs | Graph motifs
count_multiple | Find the multiple or loop edges in a graph
count_subgraph_isomorphisms | Count the isomorphic mappings between a graph and the subgraphs of another graph
count_triangles | Find triangles in graphs
create.communities | Creates a communities object.
crossing | Functions to deal with the result of network community detection
curve_multiple | Optimal edge curvature when plotting graphs
cutat | Functions to deal with the result of network community detection
cut_at | Functions to deal with the result of network community detection

## -- D --

decompose | Decompose a graph into components
decompose.graph | Decompose a graph into components
degree | Degree and degree distribution of the vertices
degree.distribution | Degree and degree distribution of the vertices
degree.sequence.game | Generate random graphs with a given degree sequence
degree_distribution | Degree and degree distribution of the vertices
degseq | Generate random graphs with a given degree sequence
delete.edges | Delete edges from a graph
delete.vertices | Delete vertices from a graph
delete_edges | Delete edges from a graph
delete_edge_attr | Delete an edge attribute
delete_graph_attr | Delete a graph attribute
delete_vertex_attr | Delete a vertex attribute
delete_vertices | Delete vertices from a graph
dendPlot | Community structure dendrogram plots
de_bruijn_graph | De Bruijn graphs
dfs | Depth-first search
diameter | Diameter of a graph
difference | Difference of two sets
difference.igraph | Difference of graphs
difference.igraph.es | Difference of edge sequences
difference.igraph.vs | Difference of vertex sequences
dim_select | Dimensionality selection for singular values using profile likelihood.
directed_graph | Create an igraph graph from a list of edges, or a notable graph
disjoint_union | Disjoint union of graphs
distances | Shortest (directed or undirected) paths between vertices
distance_table | Shortest (directed or undirected) paths between vertices
diverging_pal | Diverging palette
diversity | Graph diversity
DL | Reading foreign file formats
dominator.tree | Dominator tree
dominator_tree | Dominator tree
dot-data | '.data' and '.env' pronouns
dot-env | '.data' and '.env' pronouns
dot_product | Generate random graphs according to the random dot product graph model
drl_defaults | The DrL graph layout generator
dyad.census | Dyad census of a graph
dyad_census | Dyad census of a graph

## -- E --

E | Edges of a graph
E<- | Query or set attributes of the edges in an edge sequence
each_edge | Rewires the endpoints of the edges of a graph to a random vertex
eccentricity | Eccentricity of the vertices in a graph
ecount | The size of the graph (number of edges)
edge | Helper function for adding and deleting edges
edge.attributes | Query edge attributes of a graph
edge.attributes<- | Set one or more edge attributes
edge.betweenness | Vertex and edge betweenness centrality
edge.betweenness.community | Community structure detection based on edge betweenness
edge.betweenness.estimate | Vertex and edge betweenness centrality
edge.connectivity | Edge connectivity.
edge.disjoint.paths | Edge connectivity.
edges | Helper function for adding and deleting edges
edge_attr | Query edge attributes of a graph
edge_attr<- | Set one or more edge attributes
edge_attr_names | List names of edge attributes
edge_betweenness | Vertex and edge betweenness centrality
edge_connectivity | Edge connectivity.
edge_density | Graph density
edge_disjoint_paths | Edge connectivity.
ego | Neighborhood of graph vertices
ego_graph | Neighborhood of graph vertices
ego_size | Neighborhood of graph vertices
eigen_centrality | Find Eigenvector Centrality Scores of Network Positions
embed_adjacency_matrix | Spectral Embedding of Adjacency Matrices
embed_laplacian_matrix | Spectral Embedding of the Laplacian of a Graph
empty_graph | A graph with no edges
ends | Incident vertices of some graph edges
erdos.renyi.game | Generate random graphs according to the Erdos-Renyi model
establishment.game | Graph generation based on different vertex types
estimate_betweenness | Vertex and edge betweenness centrality
estimate_closeness | Closeness centrality of vertices
estimate_edge_betweenness | Vertex and edge betweenness centrality
eulerian_cycle | Find Eulerian paths or cycles in a graph
eulerian_path | Find Eulerian paths or cycles in a graph
evcent | Find Eigenvector Centrality Scores of Network Positions
exportPajek | Calculate Cohesive Blocks
export_pajek | Calculate Cohesive Blocks

## -- F --

farthest.nodes | Diameter of a graph
farthest_vertices | Diameter of a graph
fastgreedy.community | Community structure via greedy optimization of modularity
feedback_arc_set | Finding a feedback arc set in a graph
fit_hrg | Fit a hierarchical random graph model
fit_power_law | Fitting a power-law distribution function to discrete data
forest.fire.game | Forest Fire Network Model
from_adjacency | Create graphs from adjacency matrices
from_data_frame | Creating igraph graphs from data frames or vice-versa
from_edgelist | Create a graph from an edge list matrix
from_incidence_matrix | Create graphs from an incidence matrix
from_literal | Creating (small) graphs via a simple interface
from_prufer | Create an undirected tree graph from its Prufer sequence
full_bipartite_graph | Create a full bipartite graph
full_citation_graph | Create a complete (full) citation graph
full_graph | Create a full graph

## -- G --

get.adjacency | Convert a graph to an adjacency matrix
get.adjedgelist | Adjacency lists
get.adjlist | Adjacency lists
get.all.shortest.paths | Shortest (directed or undirected) paths between vertices
get.data.frame | Creating igraph graphs from data frames or vice-versa
get.diameter | Diameter of a graph
get.edge | Incident vertices of some graph edges
get.edge.attribute | Query edge attributes of a graph
get.edge.ids | Find the edge ids based on the incident vertices of the edges
get.edgelist | Convert a graph to an edge list
get.edges | Incident vertices of some graph edges
get.graph.attribute | Graph attributes of a graph
get.incidence | Incidence matrix of a bipartite graph
get.shortest.paths | Shortest (directed or undirected) paths between vertices
get.stochastic | Stochastic matrix of a graph
get.vertex.attribute | Query vertex attributes of a graph
getIgraphOpt | Parameters for the igraph package
get_diameter | Diameter of a graph
girth | Girth of a graph
global_efficiency | Efficiency of a graph
GML | Reading foreign file formats
gnm | Generate random graphs according to the G(n,m) Erdos-Renyi model
gnp | Generate random graphs according to the G(n,p) Erdos-Renyi model
gorder | Order (number of vertices) of a graph
graph | Create an igraph graph from a list of edges, or a notable graph
graph.adhesion | Edge connectivity.
graph.adjacency | Create graphs from adjacency matrices
graph.adjlist | Create graphs from adjacency lists
graph.atlas | Create a graph from the Graph Atlas
graph.attributes | Graph attributes of a graph
graph.attributes<- | Set all or some graph attributes
graph.automorphisms | Number of automorphisms
graph.bfs | Breadth-first search
graph.bipartite | Create a bipartite graph
graph.cohesion | Vertex connectivity.
graph.complementer | Complementer of a graph
graph.compose | Compose two graphs as binary relations
graph.coreness | K-core decomposition of graphs
graph.count.isomorphisms.vf2 | Count the number of isomorphic mappings between two graphs
graph.count.subisomorphisms.vf2 | Count the isomorphic mappings between a graph and the subgraphs of another graph
graph.data.frame | Creating igraph graphs from data frames or vice-versa
graph.de.bruijn | De Bruijn graphs
graph.density | Graph density
graph.dfs | Depth-first search
graph.difference | Difference of graphs
graph.disjoint.union | Disjoint union of graphs
graph.diversity | Graph diversity
graph.edgelist | Create a graph from an edge list matrix
graph.eigen | Eigenvalues and eigenvectors of the adjacency matrix of a graph
graph.empty | A graph with no edges
graph.extended.chordal.ring | Create an extended chordal ring graph
graph.famous | Create an igraph graph from a list of edges, or a notable graph
graph.formula | Creating (small) graphs via a simple interface
graph.full | Create a full graph
graph.full.bipartite | Create a full bipartite graph
graph.full.citation | Create a complete (full) citation graph
graph.get.isomorphisms.vf2 | Calculate all isomorphic mappings between the vertices of two graphs
graph.get.subisomorphisms.vf2 | All isomorphic mappings between a graph and subgraphs of another graph
graph.graphdb | Load a graph from the graph database for testing graph isomorphism.
graph.incidence | Create graphs from an incidence matrix
graph.intersection | Intersection of graphs
graph.isoclass | Isomorphism class of a graph
graph.isoclass.subgraph | Isomorphism class of a graph
graph.isocreate | Create a graph from an isomorphism class
graph.isomorphic | Decide if two graphs are isomorphic
graph.isomorphic.34 | Decide if two graphs are isomorphic
graph.isomorphic.bliss | Decide if two graphs are isomorphic
graph.isomorphic.vf2 | Decide if two graphs are isomorphic
graph.kautz | Kautz graphs
graph.knn | Average nearest neighbor degree
graph.laplacian | Graph Laplacian
graph.lattice | Create a lattice graph
graph.lcf | Creating a graph from LCF notation
graph.maxflow | Maximum flow in a graph
graph.mincut | Minimum cut in a graph
graph.motifs | Graph motifs
graph.motifs.est | Graph motifs
graph.motifs.no | Graph motifs
graph.neighborhood | Neighborhood of graph vertices
graph.ring | Create a ring graph
graph.star | Create a star graph, a tree with n vertices and n - 1 leaves
graph.strength | Strength or weighted vertex degree
graph.subisomorphic.lad | Decide if a graph is subgraph isomorphic to another one
graph.subisomorphic.vf2 | Decide if a graph is subgraph isomorphic to another one
graph.tree | Create tree graphs
graph.union | Union of graphs
graphlets | Graphlet decomposition of a graph
graphlets.candidate.basis | Graphlet decomposition of a graph
graphlets.project | Graphlet decomposition of a graph
graphlet_basis | Graphlet decomposition of a graph
graphlet_proj | Graphlet decomposition of a graph
GraphML | Reading foreign file formats
graphs_from_cohesive_blocks | Calculate Cohesive Blocks
graph_ | Convert object to a graph
graph_attr | Graph attributes of a graph
graph_attr<- | Set all or some graph attributes
graph_attr_names | List names of graph attributes
graph_from_adjacency_matrix | Create graphs from adjacency matrices
graph_from_adj_list | Create graphs from adjacency lists
graph_from_atlas | Create a graph from the Graph Atlas
graph_from_data_frame | Creating igraph graphs from data frames or vice-versa
graph_from_edgelist | Create a graph from an edge list matrix
graph_from_graphdb | Load a graph from the graph database for testing graph isomorphism.
graph_from_graphnel | Convert graphNEL objects from the graph package to igraph
graph_from_incidence_matrix | Create graphs from an incidence matrix
graph_from_isomorphism_class | Create a graph from an isomorphism class
graph_from_lcf | Creating a graph from LCF notation
graph_from_literal | Creating (small) graphs via a simple interface
graph_id | Get the id of a graph
graph_version | igraph data structure versions
greedy_vertex_coloring | Greedy vertex coloring
grg | Geometric random graphs
grg.game | Geometric random graphs
groups | Groups of a vertex partitioning
groups.communities | Groups of a vertex partitioning
groups.default | Groups of a vertex partitioning
growing | Growing random graph generation
growing.random.game | Growing random graph generation
gsize | The size of the graph (number of edges)

## -- H --

harmonic_centrality | Harmonic centrality of vertices
has.multiple | Find the multiple or loop edges in a graph
has_eulerian_cycle | Find Eulerian paths or cycles in a graph
has_eulerian_path | Find Eulerian paths or cycles in a graph
head_of | Head of the edge(s) in a graph
head_print | Print the only the head of an R object
hierarchical_sbm | Sample the hierarchical stochastic block model
hierarchy | Calculate Cohesive Blocks
hrg | Create a hierarchical random graph from an igraph graph
hrg-methods | Hierarchical random graphs
hrg.consensus | Create a consensus tree from several hierarchical random graph models
hrg.create | Create a hierarchical random graph from an igraph graph
hrg.dendrogram | HRG dendrogram plot
hrg.fit | Fit a hierarchical random graph model
hrg.game | Sample from a hierarchical random graph model
hrg.predict | Predict edges based on a hierarchical random graph model
hrg_tree | Create an igraph graph from a hierarchical random graph model
hub.score | Kleinberg's hub centrality scores.
hub_score | Kleinberg's hub centrality scores.

## -- I --

identical_graphs | Decide if two graphs are identical
igraph | The igraph package
igraph-attribute-combination | How igraph functions handle attributes when the graph changes
igraph-dollar | Getting and setting graph attributes, shortcut
igraph-es-attributes | Query or set attributes of the edges in an edge sequence
igraph-es-indexing | Indexing edge sequences
igraph-es-indexing2 | Select edges and show their metadata
igraph-minus | Delete vertices or edges from a graph
igraph-vs-attributes | Query or set attributes of the vertices in a vertex sequence
igraph-vs-indexing | Indexing vertex sequences
igraph-vs-indexing2 | Select vertices and show their metadata
igraph.arpack.default | ARPACK eigenvector calculation
igraph.console | The igraph console
igraph.drl.coarsen | The DrL graph layout generator
igraph.drl.coarsest | The DrL graph layout generator
igraph.drl.default | The DrL graph layout generator
igraph.drl.final | The DrL graph layout generator
igraph.drl.refine | The DrL graph layout generator
igraph.eigen.default | Eigenvalues and eigenvectors of the adjacency matrix of a graph
igraph.from.graphNEL | Convert graphNEL objects from the graph package to igraph
igraph.options | Parameters for the igraph package
igraph.plotting | Drawing graphs
igraph.sample | Sampling a random integer sequence
igraph.shape.noclip | Various vertex shapes when plotting igraph graphs
igraph.shape.noplot | Various vertex shapes when plotting igraph graphs
igraph.to.graphNEL | Convert igraph graphs to graphNEL objects from the graph package
igraph.version | Query igraph's version string
igraph.vertex.shapes | Various vertex shapes when plotting igraph graphs
igraphdemo | Run igraph demos, step by step
igraphtest | Run package tests
igraph_demo | Run igraph demos, step by step
igraph_opt | Parameters for the igraph package
igraph_options | Parameters for the igraph package
igraph_test | Run package tests
igraph_version | Query igraph's version string
incident | Incident edges of a vertex in a graph
incident_edges | Incident edges of multiple vertices in a graph
indent_print | Indent a printout
independence.number | Independent vertex sets
independent.vertex.sets | Independent vertex sets
induced.subgraph | Subgraph of a graph
induced_subgraph | Subgraph of a graph
infomap.community | Infomap community finding
interconnected.islands.game | A graph with subgraphs that are each a random graph.
intersection | Intersection of two or more sets
intersection.igraph | Intersection of graphs
intersection.igraph.es | Intersection of edge sequences
intersection.igraph.vs | Intersection of vertex sequences
in_circle | Graph layout with vertices on a circle.
is.bipartite | Create a bipartite graph
is.chordal | Chordality of a graph
is.connected | Connected components of a graph
is.dag | Directed acyclic graphs
is.degree.sequence | Check if a degree sequence is valid for a multi-graph
is.directed | Check whether a graph is directed
is.graphical.degree.sequence | Is a degree sequence graphical?
is.hierarchical | Functions to deal with the result of network community detection
is.igraph | Is this object an igraph graph?
is.loop | Find the multiple or loop edges in a graph
is.matching | Graph matching
is.maximal.matching | Graph matching
is.minimal.separator | Minimal vertex separators
is.multiple | Find the multiple or loop edges in a graph
is.mutual | Find mutual edges in a directed graph
is.named | Named graphs
is.separator | Vertex separators
is.simple | Simple graphs
is.weighted | Weighted graphs
isomorphic | Decide if two graphs are isomorphic
isomorphisms | Calculate all isomorphic mappings between the vertices of two graphs
isomorphism_class | Isomorphism class of a graph
is_bipartite | Create a bipartite graph
is_chordal | Chordality of a graph
is_connected | Connected components of a graph
is_dag | Directed acyclic graphs
is_degseq | Check if a degree sequence is valid for a multi-graph
is_directed | Check whether a graph is directed
is_graphical | Is a degree sequence graphical?
is_hierarchical | Functions to deal with the result of network community detection
is_igraph | Is this object an igraph graph?
is_isomorphic_to | Decide if two graphs are isomorphic
is_matching | Graph matching
is_max_matching | Graph matching
is_min_separator | Minimal vertex separators
is_named | Named graphs
is_printer_callback | Is this a printer callback?
is_separator | Vertex separators
is_simple | Simple graphs
is_subgraph_isomorphic_to | Decide if a graph is subgraph isomorphic to another one
is_tree | Decide whether a graph is a tree.
is_weighted | Weighted graphs
ivs | Independent vertex sets
ivs_size | Independent vertex sets

## -- K --

k.regular.game | Create a random regular graph
kautz_graph | Kautz graphs
keeping_degseq | Graph rewiring while preserving the degree distribution
knn | Average nearest neighbor degree

## -- L --

label.propagation.community | Finding communities based on propagating labels
laplacian_matrix | Graph Laplacian
largest.cliques | Functions to find cliques, ie. complete subgraphs in a graph
largest.independent.vertex.sets | Independent vertex sets
largest_cliques | Functions to find cliques, ie. complete subgraphs in a graph
largest_ivs | Independent vertex sets
largest_weighted_cliques | Functions to find weighted cliques, ie. weighted complete subgraphs in a graph
lastcit.game | Random citation graphs
last_cit | Random citation graphs
lattice | Create a lattice graph
layout | Graph layouts
layout.auto | Choose an appropriate graph layout algorithm automatically
layout.bipartite | Simple two-row layout for bipartite graphs
layout.circle | Deprecated layout functions
layout.davidson.harel | The Davidson-Harel layout algorithm
layout.drl | The DrL graph layout generator
layout.fruchterman.reingold | Deprecated layout functions
layout.fruchterman.reingold.grid | Grid Fruchterman-Reingold layout, this was removed from igraph
layout.gem | The GEM layout algorithm
layout.graphopt | The graphopt layout algorithm
layout.grid | Simple grid layout
layout.grid.3d | Simple grid layout
layout.kamada.kawai | Deprecated layout functions
layout.lgl | Deprecated layout functions
layout.mds | Graph layout by multidimensional scaling
layout.merge | Merging graph layouts
layout.norm | Normalize coordinates for plotting graphs
layout.random | Deprecated layout functions
layout.reingold.tilford | Deprecated layout functions
layout.sphere | Deprecated layout functions
layout.spring | Spring layout, this was removed from igraph
layout.star | Generate coordinates to place the vertices of a graph in a star-shape
layout.sugiyama | The Sugiyama graph layout generator
layout.svd | SVD layout, this was removed from igraph
layout_ | Graph layouts
layout_as_bipartite | Simple two-row layout for bipartite graphs
layout_as_star | Generate coordinates to place the vertices of a graph in a star-shape
layout_as_tree | The Reingold-Tilford graph layout algorithm
layout_components | Merging graph layouts
layout_in_circle | Graph layout with vertices on a circle.
layout_nicely | Choose an appropriate graph layout algorithm automatically
layout_on_grid | Simple grid layout
layout_on_sphere | Graph layout with vertices on the surface of a sphere
layout_randomly | Randomly place vertices on a plane or in 3d space
layout_with_dh | The Davidson-Harel layout algorithm
layout_with_drl | The DrL graph layout generator
layout_with_fr | The Fruchterman-Reingold layout algorithm
layout_with_gem | The GEM layout algorithm
layout_with_graphopt | The graphopt layout algorithm
layout_with_kk | The Kamada-Kawai layout algorithm
layout_with_lgl | Large Graph Layout
layout_with_mds | Graph layout by multidimensional scaling
layout_with_sugiyama | The Sugiyama graph layout generator
leading.eigenvector.community | Community structure detecting based on the leading eigenvector of the community matrix
length.cohesiveBlocks | Calculate Cohesive Blocks
length.communities | Functions to deal with the result of network community detection
LGL | Reading foreign file formats
line.graph | Line graph of a graph
line_graph | Line graph of a graph
list.edge.attributes | List names of edge attributes
list.graph.attributes | List names of graph attributes
list.vertex.attributes | List names of vertex attributes
local_efficiency | Efficiency of a graph
local_scan | Compute local scan statistics on graphs

## -- M --

make_ | Make a new graph
make_bipartite_graph | Create a bipartite graph
make_chordal_ring | Create an extended chordal ring graph
make_clusters | Creates a communities object.
make_de_bruijn_graph | De Bruijn graphs
make_directed_graph | Create an igraph graph from a list of edges, or a notable graph
make_ego_graph | Neighborhood of graph vertices
make_empty_graph | A graph with no edges
make_from_prufer | Create an undirected tree graph from its Prufer sequence
make_full_bipartite_graph | Create a full bipartite graph
make_full_citation_graph | Create a complete (full) citation graph
make_full_graph | Create a full graph
make_graph | Create an igraph graph from a list of edges, or a notable graph
make_kautz_graph | Kautz graphs
make_lattice | Create a lattice graph
make_line_graph | Line graph of a graph
make_ring | Create a ring graph
make_star | Create a star graph, a tree with n vertices and n - 1 leaves
make_tree | Create tree graphs
make_undirected_graph | Create an igraph graph from a list of edges, or a notable graph
match_vertices | Match Graphs given a seeding of vertex correspondences
maxcohesion | Calculate Cohesive Blocks
maximal.cliques | Functions to find cliques, ie. complete subgraphs in a graph
maximal.cliques.count | Functions to find cliques, ie. complete subgraphs in a graph
maximal.independent.vertex.sets | Independent vertex sets
maximal_ivs | Independent vertex sets
maximum.bipartite.matching | Graph matching
maximum.cardinality.search | Maximum cardinality search
max_bipartite_match | Graph matching
max_cardinality | Maximum cardinality search
max_cliques | Functions to find cliques, ie. complete subgraphs in a graph
max_cohesion | Calculate Cohesive Blocks
max_flow | Maximum flow in a graph
max_weighted_cliques | Functions to find weighted cliques, ie. weighted complete subgraphs in a graph
mean_distance | Shortest (directed or undirected) paths between vertices
median.sir | SIR model on graphs
membership | Functions to deal with the result of network community detection
merges | Functions to deal with the result of network community detection
merge_coords | Merging graph layouts
minimal.st.separators | Minimum size vertex separators
minimum.size.separators | Minimum size vertex separators
minimum.spanning.tree | Minimum spanning tree
min_cut | Minimum cut in a graph
min_separators | Minimum size vertex separators
min_st_separators | Minimum size vertex separators
mod.matrix | Modularity of a community structure of a graph
modularity | Modularity of a community structure of a graph
modularity.communities | Functions to deal with the result of network community detection
modularity.igraph | Modularity of a community structure of a graph
modularity_matrix | Modularity of a community structure of a graph
motifs | Graph motifs
mst | Minimum spanning tree
multilevel.community | Finding community structure by multi-level optimization of modularity

## -- N --

neighborhood | Neighborhood of graph vertices
neighborhood.size | Neighborhood of graph vertices
neighbors | Neighboring (adjacent) vertices in a graph
nexus | Query and download from the Nexus network repository
nexus.get | Query and download from the Nexus network repository
nexus.info | Query and download from the Nexus network repository
nexus.list | Query and download from the Nexus network repository
nexus.search | Query and download from the Nexus network repository
nexusDatasetInfo | Query and download from the Nexus network repository
nexus_get | Query and download from the Nexus network repository
nexus_info | Query and download from the Nexus network repository
nexus_list | Query and download from the Nexus network repository
nexus_search | Query and download from the Nexus network repository
nicely | Choose an appropriate graph layout algorithm automatically
no.clusters | Connected components of a graph
normalize | Normalize layout
norm_coords | Normalize coordinates for plotting graphs

## -- O --

on_grid | Simple grid layout
on_sphere | Graph layout with vertices on the surface of a sphere
optimal.community | Optimal community structure

## -- P --

pa | Generate random graphs using preferential attachment
page.rank | The Page Rank algorithm
page_rank | The Page Rank algorithm
Pajek | Reading foreign file formats
parent | Calculate Cohesive Blocks
path | Helper function to add or delete edges along a path
path.length.hist | Shortest (directed or undirected) paths between vertices
pa_age | Generate an evolving random graph with preferential attachment and aging
permute | Permute the vertices of a graph
permute.vertices | Permute the vertices of a graph
piecewise.layout | Merging graph layouts
plot.cohesiveBlocks | Calculate Cohesive Blocks
plot.communities | Functions to deal with the result of network community detection
plot.graph | Plotting of graphs
plot.igraph | Plotting of graphs
plot.sir | Plotting the results on multiple SIR model runs
plotHierarchy | Calculate Cohesive Blocks
plot_dendrogram | Community structure dendrogram plots
plot_dendrogram.communities | Community structure dendrogram plots
plot_dendrogram.igraphHRG | HRG dendrogram plot
plot_hierarchy | Calculate Cohesive Blocks
power.law.fit | Fitting a power-law distribution function to discrete data
power_centrality | Find Bonacich Power Centrality Scores of Network Positions
predict_edges | Predict edges based on a hierarchical random graph model
pref | Trait-based random generation
preference.game | Trait-based random generation
print.cohesiveBlocks | Calculate Cohesive Blocks
print.communities | Functions to deal with the result of network community detection
print.igraph | Print graphs to the terminal
print.igraph.es | Print an edge sequence to the screen
print.igraph.vs | Show a vertex sequence on the screen
print.igraphHRG | Print a hierarchical random graph model to the screen
print.igraphHRGConsensus | Print a hierarchical random graph consensus tree to the screen
print.igraph_layout_modifier | Graph layouts
print.igraph_layout_spec | Graph layouts
print.nexusDatasetInfo | Query and download from the Nexus network repository
print.nexusDatasetInfoList | Query and download from the Nexus network repository
printer_callback | Create a printer callback function
printr | Better printing of R packages
print_all | Print graphs to the terminal

## -- Q --

quantile.sir | SIR model on graphs

## -- R --

radius | Radius of a graph
random.graph.game | Generate random graphs according to the Erdos-Renyi model
randomly | Randomly place vertices on a plane or in 3d space
random_edge_walk | Random walk on a graph
random_walk | Random walk on a graph
read.graph | Reading foreign file formats
read_graph | Reading foreign file formats
realize_degseq | Creating a graph from a given degree sequence, deterministically
reciprocity | Reciprocity of graphs
remove.edge.attribute | Delete an edge attribute
remove.graph.attribute | Delete a graph attribute
remove.vertex.attribute | Delete a vertex attribute
rep.igraph | Replicate a graph multiple times
rev.igraph.es | Reverse the order in an edge sequence
rev.igraph.vs | Reverse the order in a vertex sequence
reverse_edges | Reverse edges in a graph
rewire | Rewiring edges of a graph
rglplot | 3D plotting of graphs with OpenGL
rglplot.igraph | 3D plotting of graphs with OpenGL
ring | Create a ring graph
running.mean | Running mean of a time series
running_mean | Running mean of a time series
r_pal | The default R palette

## -- S --

sample_ | Sample from a random graph model
sample_asym_pref | Trait-based random generation
sample_bipartite | Bipartite random graphs
sample_cit_cit_types | Random citation graphs
sample_cit_types | Random citation graphs
sample_correlated_gnp | Generate a new random graph from a given graph by randomly adding/removing edges
sample_correlated_gnp_pair | Sample a pair of correlated G(n,p) random graphs
sample_degseq | Generate random graphs with a given degree sequence
sample_dirichlet | Sample from a Dirichlet distribution
sample_dot_product | Generate random graphs according to the random dot product graph model
sample_fitness | Random graphs from vertex fitness scores
sample_fitness_pl | Scale-free random graphs, from vertex fitness scores
sample_forestfire | Forest Fire Network Model
sample_gnm | Generate random graphs according to the G(n,m) Erdos-Renyi model
sample_gnp | Generate random graphs according to the G(n,p) Erdos-Renyi model
sample_grg | Geometric random graphs
sample_growing | Growing random graph generation
sample_hierarchical_sbm | Sample the hierarchical stochastic block model
sample_hrg | Sample from a hierarchical random graph model
sample_islands | A graph with subgraphs that are each a random graph.
sample_k_regular | Create a random regular graph
sample_last_cit | Random citation graphs
sample_motifs | Graph motifs
sample_pa | Generate random graphs using preferential attachment
sample_pa_age | Generate an evolving random graph with preferential attachment and aging
sample_pref | Trait-based random generation
sample_sbm | Sample stochastic block model
sample_seq | Sampling a random integer sequence
sample_smallworld | The Watts-Strogatz small-world model
sample_spanning_tree | Samples from the spanning trees of a graph randomly and uniformly
sample_sphere_surface | Sample vectors uniformly from the surface of a sphere
sample_sphere_volume | Sample vectors uniformly from the volume of a sphere
sample_traits | Graph generation based on different vertex types
sample_traits_callaway | Graph generation based on different vertex types
sample_tree | Sample trees randomly and uniformly
sbm | Sample stochastic block model
sbm.game | Sample stochastic block model
scan_stat | Scan statistics on a time series of graphs
scg | All-in-one Function for the SCG of Matrices and Graphs
scg-method | Spectral Coarse Graining
scgGrouping | SCG Problem Solver
scgNormEps | Error of the spectral coarse graining (SCG) approximation
scgSemiProjectors | Semi-Projectors
scg_eps | Error of the spectral coarse graining (SCG) approximation
scg_group | SCG Problem Solver
scg_semi_proj | Semi-Projectors
seeded.graph.match | Match Graphs given a seeding of vertex correspondences
sequential_pal | Sequential palette
set.edge.attribute | Set edge attributes
set.graph.attribute | Set a graph attribute
set.vertex.attribute | Set vertex attributes
set_edge_attr | Set edge attributes
set_graph_attr | Set a graph attribute
set_vertex_attr | Set vertex attributes
shapes | Various vertex shapes when plotting igraph graphs
shape_noclip | Various vertex shapes when plotting igraph graphs
shape_noplot | Various vertex shapes when plotting igraph graphs
shortest.paths | Shortest (directed or undirected) paths between vertices
shortest_paths | Shortest (directed or undirected) paths between vertices
showtrace | Functions to deal with the result of network community detection
show_trace | Functions to deal with the result of network community detection
similarity | Similarity measures of two vertices
similarity.dice | Similarity measures of two vertices
similarity.invlogweighted | Similarity measures of two vertices
similarity.jaccard | Similarity measures of two vertices
simplified | Constructor modifier to drop multiple and loop edges
simplify | Simple graphs
simplify_and_colorize | Simple graphs
sir | SIR model on graphs
sizes | Functions to deal with the result of network community detection
smallworld | The Watts-Strogatz small-world model
spectrum | Eigenvalues and eigenvectors of the adjacency matrix of a graph
spinglass.community | Finding communities in graphs based on statistical meachanics
split_join_distance | Split-join distance of two community structures
srand | Deprecated function, used to set random seed of the C library's RNG
star | Create a star graph, a tree with n vertices and n - 1 leaves
static.fitness.game | Random graphs from vertex fitness scores
static.power.law.game | Scale-free random graphs, from vertex fitness scores
stCuts | List all (s,t)-cuts of a graph
stMincuts | List all minimum (s,t)-cuts of a graph
stochastic_matrix | Stochastic matrix of a graph
str.igraph | Print graphs to the terminal
strength | Strength or weighted vertex degree
st_cuts | List all (s,t)-cuts of a graph
st_min_cuts | List all minimum (s,t)-cuts of a graph
subcomponent | In- or out- component of a vertex
subgraph | Subgraph of a graph
subgraph.centrality | Find subgraph centrality scores of network positions
subgraph.edges | Subgraph of a graph
subgraph_centrality | Find subgraph centrality scores of network positions
subgraph_isomorphic | Decide if a graph is subgraph isomorphic to another one
subgraph_isomorphisms | All isomorphic mappings between a graph and subgraphs of another graph
summary.cohesiveBlocks | Calculate Cohesive Blocks
summary.igraph | Print graphs to the terminal
summary.nexusDatasetInfoList | Query and download from the Nexus network repository

## -- T --

t.igraph | Reverse edges in a graph
tail_of | Tails of the edge(s) in a graph
time_bins | SIR model on graphs
time_bins.sir | SIR model on graphs
tkigraph | Experimental basic igraph GUI
tkplot | Interactive plotting of graphs
tkplot.canvas | Interactive plotting of graphs
tkplot.center | Interactive plotting of graphs
tkplot.close | Interactive plotting of graphs
tkplot.export.postscript | Interactive plotting of graphs
tkplot.fit.to.screen | Interactive plotting of graphs
tkplot.getcoords | Interactive plotting of graphs
tkplot.off | Interactive plotting of graphs
tkplot.reshape | Interactive plotting of graphs
tkplot.rotate | Interactive plotting of graphs
tkplot.setcoords | Interactive plotting of graphs
tk_canvas | Interactive plotting of graphs
tk_center | Interactive plotting of graphs
tk_close | Interactive plotting of graphs
tk_coords | Interactive plotting of graphs
tk_fit | Interactive plotting of graphs
tk_off | Interactive plotting of graphs
tk_postscript | Interactive plotting of graphs
tk_reshape | Interactive plotting of graphs
tk_rotate | Interactive plotting of graphs
tk_set_coords | Interactive plotting of graphs
topological.sort | Topological sorting of vertices in a graph
topo_sort | Topological sorting of vertices in a graph
to_prufer | Convert a tree graph to its Prufer sequence
traits | Graph generation based on different vertex types
traits_callaway | Graph generation based on different vertex types
transitivity | Transitivity of a graph
tree | Create tree graphs
triad.census | Triad census, subgraphs with three vertices
triad_census | Triad census, subgraphs with three vertices
triangles | Find triangles in graphs

## -- U --

UCINET | Reading foreign file formats
undirected_graph | Create an igraph graph from a list of edges, or a notable graph
unfold.tree | Convert a general graph into a forest
unfold_tree | Convert a general graph into a forest
union | Union of two or more sets
union.igraph | Union of graphs
union.igraph.es | Union of edge sequences
union.igraph.vs | Union of vertex sequences
unique.igraph.es | Remove duplicate edges from an edge sequence
unique.igraph.vs | Remove duplicate vertices from a vertex sequence
upgrade_graph | igraph data structure versions

## -- V --

V | Vertices of a graph
V<- | Query or set attributes of the vertices in a vertex sequence
vcount | Order (number of vertices) of a graph
vertex | Helper function for adding and deleting vertices
vertex.attributes | Query vertex attributes of a graph
vertex.attributes<- | Set one or more vertex attributes
vertex.connectivity | Vertex connectivity.
vertex.disjoint.paths | Vertex connectivity.
vertex.shape.pie | Using pie charts as vertices in graph plots
vertex.shapes | Various vertex shapes when plotting igraph graphs
vertex_attr | Query vertex attributes of a graph
vertex_attr<- | Set one or more vertex attributes
vertex_attr_names | List names of vertex attributes
vertex_connectivity | Vertex connectivity.
vertex_disjoint_paths | Vertex connectivity.
vertices | Helper function for adding and deleting vertices

## -- W --

walktrap.community | Community structure via short random walks
watts.strogatz.game | The Watts-Strogatz small-world model
weighted_cliques | Functions to find weighted cliques, ie. weighted complete subgraphs in a graph
weighted_clique_num | Functions to find weighted cliques, ie. weighted complete subgraphs in a graph
which_loop | Find the multiple or loop edges in a graph
which_multiple | Find the multiple or loop edges in a graph
which_mutual | Find mutual edges in a directed graph
without_attr | Construtor modifier to remove all attributes from a graph
without_loops | Constructor modifier to drop loop edges
without_multiples | Constructor modifier to drop multiple edges
with_dh | The Davidson-Harel layout algorithm
with_drl | The DrL graph layout generator
with_edge_ | Constructor modifier to add edge attributes
with_fr | The Fruchterman-Reingold layout algorithm
with_gem | The GEM layout algorithm
with_graphopt | The graphopt layout algorithm
with_graph_ | Constructor modifier to add graph attributes
with_igraph_opt | Run code with a temporary igraph options setting
with_kk | The Kamada-Kawai layout algorithm
with_lgl | Large Graph Layout
with_mds | Graph layout by multidimensional scaling
with_sugiyama | The Sugiyama graph layout generator
with_vertex_ | Constructor modifier to add vertex attributes
write.graph | Writing the graph to a file in some format
write_graph | Writing the graph to a file in some format

## -- misc --

$.igraph | Getting and setting graph attributes, shortcut
$.igraph.es | Query or set attributes of the edges in an edge sequence
$.igraph.vs | Query or set attributes of the vertices in a vertex sequence
$<-.igraph | Getting and setting graph attributes, shortcut
$<-.igraph.es | Query or set attributes of the edges in an edge sequence
$<-.igraph.vs | Query or set attributes of the vertices in a vertex sequence
%--% | Indexing edge sequences
%->% | Indexing edge sequences
%<-% | Indexing edge sequences
%>% | Magrittr's pipes
%c% | Compose two graphs as binary relations
%du% | Disjoint union of graphs
%m% | Difference of graphs
%s% | Intersection of graphs
%u% | Union of graphs
*.igraph | Replicate a graph multiple times
+.igraph | Add vertices, edges or another graph to a graph
-.igraph | Delete vertices or edges from a graph
.apply_modifiers | Applies a set of constructor modifiers to an already constructed graph.
.data | '.data' and '.env' pronouns
.env | '.data' and '.env' pronouns
.extract_constructor_and_modifiers | Takes an argument list and extracts the constructor specification and constructor modifiers from it.
[.igraph | Query and manipulate a graph as it were an adjacency matrix
[.igraph.es | Indexing edge sequences
[.igraph.vs | Indexing vertex sequences
[.nexusDatasetInfoList | Query and download from the Nexus network repository
[<-.igraph.es | Query or set attributes of the edges in an edge sequence
[<-.igraph.vs | Query or set attributes of the vertices in a vertex sequence
[[.igraph | Query and manipulate a graph as it were an adjacency list
[[.igraph.es | Select edges and show their metadata
[[.igraph.vs | Select vertices and show their metadata
[[<-.igraph.es | Query or set attributes of the edges in an edge sequence
[[<-.igraph.vs | Query or set attributes of the vertices in a vertex sequence