Use this if you are using igraph from R
| dot-data {igraph} | R Documentation |
.data and .env pronounsThe .data and .env pronouns make it explicit where to look up attribute
names when indexing V(g) or E(g), i.e. the vertex or edge sequence of a
graph. These pronouns are inspired by .data and .env in rlang - thanks
to Michał Bojanowski for bringing these to our attention.
The rules are simple:
.data retrieves attributes from the graph whose vertex or edge sequence
is being evaluated.
.env retrieves variables from the calling environment.
Note that .data and .env are injected dynamically into the environment
where the indexing expressions are evaluated; you cannot get access to these
objects outside the context of an indexing expression. To avoid warnings
printed by R CMD check when code containing .data and .env is checked,
you can import .data and .env from igraph if needed. Alternatively,
you can declare them explicitly with utils::globalVariables() to silence
the warnings.