R: Parameters for the igraph package

igraph_options {igraph} | R Documentation

## Parameters for the igraph package

### Description

igraph has some parameters which (usually) affect the behavior of many functions. These can be set for the whole session via `igraph_options`.

### Usage

    igraph_options(...)

    igraph_opt(x, default = NULL)

### Arguments

`...` | 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.
`x` | A character string holding an option name.
`default` | 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.

### Details

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:

add.params

  Logical scalar, whether to add model parameter to the graphs that are created by the various graph constructors. By default it is `TRUE`.

add.vertex.names

  Logical scalar, whether to add vertex names to node level indices, like degree, betweenness scores, etc. By default it is `TRUE`.

annotate.plot

  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`.

dend.plot.type

  The plotting function to use when plotting community structure dendrograms via `plot_dendrogram`

. Possible values are ‘auto’ (the default), ‘phylo’, ‘hclust’ and ‘dendrogram’. See `plot_dendrogram` for details.

edge.attr.comb

  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.

nexus.url

  The base URL of the default Nexus server. See `nexus` for details.

print.edge.attributes

  Logical constant, whether to print edge attributes when printing graphs. Defaults to `FALSE`.

print.full

  Logical scalar, whether `print.igraph` should show the graph structure as well, or only a summary of the graph.

print.graph.attributes

  Logical constant, whether to print graph attributes when printing graphs. Defaults to `FALSE`.

print.vertex.attributes

  Logical constant, whether to print vertex attributes when printing graphs. Defaults to `FALSE`.

return.vs.es

  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.

sparsematrices

  Whether to use the `Matrix` package for (sparse) matrices. It is recommended, if the user works with larger graphs.

verbose

  Logical constant, whether igraph functions should talk more than minimal. Eg. if `TRUE` thne some functions will use progress bars while computing. Defaults to `FALSE`.

vertex.attr.comb

  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.

### Value

`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.

### Author(s)

Gabor Csardi csardi.gabor@gmail.com

### See Also

`igraph_options` is similar to `options` and `igraph_opt` is similar to `getOption`.

Other igraph options: `with_igraph_opt`

### Examples

    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")

[Package igraph version 1.2.2 Index]