# Network Analysis and Visualization

## Documentation for package ‘igraph’ version 2.2.1

- DESCRIPTION file.
- User guides, package vignettes and other documentation.
- 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

## -- A --

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_vertices | Adjacent vertices of multiple vertices in a graph
algorithm | Functions to deal with the result of network community detection
align_layout | Align a vertex layout This function centers a vertex layout on the coordinate system origin and rotates the layout to achieve a visually pleasing alignment with the coordinate axes. Doing this is particularly useful with force-directed layouts such as 'layout_with_fr()'.
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
any_loop | Find the multiple or loop edges in a graph
any_multiple | Find the multiple or loop edges in a graph
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
as.dendrogram.communities | Functions to deal with the result of network community detection
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
assortativity | Assortativity coefficient
assortativity_degree | Assortativity coefficient
assortativity_nominal | Assortativity coefficient
asym_pref | Trait-based random generation
as_adjacency_matrix | Convert a graph to an adjacency matrix
as_adj_edge_list | Adjacency lists
as_adj_list | Adjacency lists
as_biadjacency_matrix | Bipartite adjacency matrix of a bipartite graph
as_bipartite | Simple two-row layout for bipartite graphs
as_data_frame | Creating igraph graphs from data frames or vice-versa
as_directed | Convert between directed and undirected graphs
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_long_data_frame | Convert a graph to a long data frame
as_membership | Declare a numeric vector as a membership vector
as_star | Generate coordinates to place the vertices of a graph in a star-shape
as_tree | The Reingold-Tilford graph layout algorithm
as_undirected | Convert between directed and undirected graphs
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.
automorphism_group | Generating set of the automorphism group of a graph
average_local_efficiency | Efficiency of a graph

## -- B --

betweenness | Vertex and edge betweenness centrality
betweenness.estimate | Vertex and edge betweenness centrality
bfs | Breadth-first search
bibcoupling | Cocitation coupling
biconnected_components | Biconnected components
bipartite | Bipartite random graphs
bipartite_gnm | Bipartite random graphs
bipartite_gnp | 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
blocks | Calculate Cohesive Blocks
bridges | Articulation points and bridges of a graph

## -- C --

c.igraph.es | Concatenate edge sequences
c.igraph.vs | Concatenate vertex sequences
canonical_permutation | Canonical permutation of a graph
categorical_pal | Palette for categories
centralization | Centralization of a graph
centralize | 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 eigenvector centralization
chordal_ring | Create an extended chordal ring graph
chung_lu | Random graph with given expected degrees
cit_cit_types | Random citation graphs
cit_types | Random citation graphs
cliques | Functions to find cliques, i.e. complete subgraphs in a graph
clique_num | Functions to find cliques, i.e. complete subgraphs in a graph
clique_size_counts | Functions to find cliques, i.e. complete subgraphs in a graph
closeness | Closeness centrality of vertices
closeness.estimate | Closeness centrality of vertices
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_len | Functions to deal with the result of network community detection
cohesion | Vertex connectivity
cohesion.cohesiveBlocks | Calculate Cohesive Blocks
cohesion.igraph | Vertex connectivity
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
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
convex_hull | Convex hull of a set of vertices
coreness | K-core decomposition of graphs
count_automorphisms | Number of automorphisms
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, i.e. 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
crossing | Functions to deal with the result of network community detection
curve_multiple | Optimal edge curvature when plotting graphs
cut_at | Functions to deal with the result of network community detection

## -- D --

decompose | Decompose a graph into components
degree | Degree and degree distribution of the vertices
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_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
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
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

## -- 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.estimate | Vertex and edge betweenness centrality
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 | Eigenvector centrality of vertices
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
eulerian_cycle | Find Eulerian paths or cycles in a graph
eulerian_path | Find Eulerian paths or cycles in a graph
export_pajek | Calculate Cohesive Blocks

## -- F --

farthest_vertices | Diameter of a graph
feedback_arc_set | Finding a feedback arc set in a graph
feedback_vertex_set | Finding a feedback vertex set in a graph
find_cycle | Finds a cycle in a graph, if there is one
fit_hrg | Fit a hierarchical random graph model
fit_power_law | Fitting a power-law distribution function to discrete data
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_literal | Creating (small) graphs via a simple interface
from_prufer | Create an undirected tree graph from its Prüfer 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.edges | Incident vertices of some graph edges
get_diameter | Diameter of a graph
get_edge_ids | Find the edge ids based on the incident vertices of the edges
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) Erdős-Rényi model
gnp | Generate random graphs according to the G(n,p) Erdős-Rényi model
gorder | Order (number of vertices) of a graph
graph.attributes | Graph attributes of a graph
graph.attributes<- | Set all or some graph attributes
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.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.isoclass | Isomorphism class of a graph
graph.isoclass.subgraph | Isomorphism class of a graph
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.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
graphlets | 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_center | Central vertices of a graph
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_biadjacency_matrix | Create graphs from a bipartite adjacency matrix
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_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
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
gsize | The size of the graph (number of edges)

## -- H --

harmonic_centrality | Harmonic centrality of vertices
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
hits_scores | Kleinberg's hub and authority centrality scores.
hrg | Create a hierarchical random graph from an igraph graph
hrg-methods | Hierarchical random graphs
hrg_tree | Create an igraph graph from a hierarchical random graph model
hub_score | Kleinberg's authority centrality scores.

## -- I --

identical_graphs | Decide if two graphs are identical
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.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.plotting | Drawing graphs
igraph.vertex.shapes | Various vertex shapes when plotting igraph graphs
igraph_opt | Parameters for the igraph package
igraph_options | Parameters for the igraph package
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
induced_subgraph | Subgraph of a 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.
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_acyclic | Acyclic graphs
is_biconnected | Check biconnectedness
is_bipartite | Checks whether the graph has a vertex attribute called 'type'.
is_chordal | Chordality of a graph
is_clique | Functions to find cliques, i.e. complete subgraphs in a graph
is_complete | Is this a complete 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_forest | Decide whether a graph is a forest.
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_ivs | Independent vertex sets
is_matching | Matching
is_max_matching | Matching
is_min_separator | Minimal vertex separators
is_named | Named graphs
is_printer_callback | Is this a printer callback?
is_separator | Check whether removing this set of vertices would disconnect the graph.
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 --

kautz_graph | Kautz graphs
keeping_degseq | Graph rewiring while preserving the degree distribution
knn | Average nearest neighbor degree
k_shortest_paths | Find the k shortest paths between two vertices

## -- L --

laplacian_matrix | Graph Laplacian
largest_cliques | Functions to find cliques, i.e. complete subgraphs in a graph
largest_component | Connected components of a graph
largest_ivs | Independent vertex sets
largest_weighted_cliques | Functions to find cliques, i.e. complete subgraphs in a graph
last_cit | Random citation graphs
lattice | Create a lattice graph
layout | Graph layouts
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
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
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 Prüfer 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_neighborhood_graph | Neighborhood of graph vertices
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
max_bipartite_match | Matching
max_cardinality | Maximum cardinality search
max_cliques | Functions to find cliques, i.e. complete subgraphs in a graph
max_cohesion | Calculate Cohesive Blocks
max_degree | Degree and degree distribution of the vertices
max_flow | Maximum flow in a graph
max_ivs | Independent vertex sets
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
min_cut | Minimum cut in a graph
min_separators | Minimum size vertex separators
min_st_separators | Minimum size vertex separators
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

## -- N --

neighborhood | Neighborhood of graph vertices
neighborhood_size | Neighborhood of graph vertices
neighbors | Neighboring (adjacent) vertices in a graph
nicely | Choose an appropriate graph layout algorithm automatically
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

## -- P --

pa | Generate random graphs using preferential attachment
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
pa_age | Generate an evolving random graph with preferential attachment and aging
permute | Permute the vertices of a graph
plot.cohesiveBlocks | Calculate Cohesive Blocks
plot.common | Drawing graphs
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
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_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
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
printer_callback | Create a printer callback function
print_all | Print graphs to the terminal

## -- Q --

quantile.sir | SIR model on graphs

## -- R --

radius | Radius of a graph
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
realize_bipartite_degseq | Creating a bipartite graph from two degree sequences, deterministically
realize_degseq | Creating a graph from a given degree sequence, deterministically
reciprocity | Reciprocity of graphs
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
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_bipartite_gnm | Bipartite random graphs
sample_bipartite_gnp | Bipartite random graphs
sample_chung_lu | Random graph with given expected degrees
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) Erdős-Rényi model
sample_gnp | Generate random graphs according to the G(n,p) Erdős-Rényi 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
scan_stat | Scan statistics on a time series of graphs
seeded.graph.match | Match Graphs given a seeding of vertex correspondences
sequential_pal | Sequential palette
set_edge_attr | Set edge attributes
set_graph_attr | Set a graph attribute
set_vertex_attr | Set vertex attributes
set_vertex_attrs | Set multiple 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
show_trace | Functions to deal with the result of network community detection
similarity | Similarity measures of two vertices
simple_cycles | Finds all simple cycles in a graph.
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
split_join_distance | Split-join distance of two community structures
star | Create a star graph, a tree with n vertices and n - 1 leaves
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_from_edges | Subgraph of a graph
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

## -- 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
tkplot | 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
topo_sort | Topological sorting of vertices in a graph
to_prufer | Convert a tree graph to its Prüfer 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
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
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.shape.pie | Using pie charts as vertices in graph plots
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
voronoi_cells | Voronoi partitioning of a graph

## -- W --

weighted_cliques | Functions to find weighted cliques, i.e. vertex-weighted complete subgraphs in a graph
weighted_clique_num | Functions to find cliques, i.e. 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

## -- 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
.data | '.data' and '.env' pronouns
.env | '.data' and '.env' pronouns
[.igraph | Query and manipulate a graph as it were an adjacency matrix
[.igraph.es | Indexing edge sequences
[.igraph.vs | Indexing vertex sequences
[<-.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