igraph has some parameters which (usually) affect the behavior of many
functions. These can be set for the whole session via igraph_options.
igraph_options(...)igraph_opt(x, default = NULL)
A list may be given as the only argument, or any number of
arguments may be in the name=value form, or no argument at all may be
given. See the Value and Details sections for explanation.
A character string holding an option name.
If the specified option is not set in the options list, this value is returned. This facilitates retrieving an option and checking whether it is set and setting it separately if not.
igraph_options returns a list with the old values of the
updated parameters, invisibly. Without any arguments, it returns the
values of all options.
For igraph_opt, the current value set for option x, or
NULL if the option is unset.
The parameter values set via a call to the igraph_options function
will remain in effect for the rest of the session, affecting the subsequent
behaviour of the other functions of the igraph package for which the
given parameters are relevant.
This offers the possibility of customizing the functioning of the
igraph package, for instance by insertions of appropriate calls to
igraph_options in a load hook for package igraph.
The currently used parameters in alphabetical order:
Logical scalar, whether to add model
parameter to the graphs that are created by the various
graph constructors. By default it is TRUE.
Logical scalar, whether to add
vertex names to node level indices, like degree, betweenness
scores, etc. By default it is TRUE.
Logical scalar, whether to annotate igraph
plots with the graph's name (name graph attribute, if
present) as main, and with the number of vertices and edges
as xlab. Defaults to FALSE.
The plotting function to use when plotting
community structure dendrograms via
plot_dendrogram
Specifies what to do with the edge
attributes if the graph is modified. The default value is
list(weight="sum", name="concat", "ignore"). See
attribute.combination for details on this.
The base URL of the default Nexus server. See
nexus for details.
Logical constant, whether to print edge
attributes when printing graphs. Defaults to FALSE.
Logical scalar, whether print.igraph
should show the graph structure as well, or only a summary of the
graph.
Logical constant, whether to print
graph attributes when printing graphs. Defaults to FALSE.
Logical constant, whether to print
vertex attributes when printing graphs. Defaults to FALSE.
Whether functions that return a set or sequence
of vertices/edges should return formal vertex/edge sequence
objects. This option was introduced in igraph version 1.0.0 and
defaults to TRUE. If your package requires the old behavior,
you can set it to FALSE in the .onLoad function of
your package, without affecting other packages.
Whether to use the Matrix package for
(sparse) matrices. It is recommended, if the user works with
larger graphs.
Logical constant, whether igraph functions should
talk more than minimal. Eg. if TRUE then some functions
will use progress bars while computing. Defaults to FALSE.
Specifies what to do with the vertex
attributes if the graph is modified. The default value is
list(name="concat", "ignore") See
attribute.combination for details on this.
igraph_options is similar to options and
igraph_opt is similar to getOption.
Other igraph options:
with_igraph_opt()
# NOT RUN {
oldval <- igraph_opt("verbose")
igraph_options(verbose = TRUE)
layout_with_kk(make_ring(10))
igraph_options(verbose = oldval)
oldval <- igraph_options(verbose = TRUE, sparsematrices = FALSE)
make_ring(10)[]
igraph_options(oldval)
igraph_opt("verbose")
# }
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