An expression that returns an R list with
named elements corresponding to the series of data to be
included in the graph. The default x variable will be the
current time; this behavior can be overridden by
providing a list element named x. Note that
name is a reserved keyword which may not be used.
env
The environment in which to evaluate
expr.
quoted
Is expr a quoted expression (with
quote())? This is useful if you want to save an
expression in a variable.
session
The current Shiny session into which we
should send the messages to update the graph.