recordGraphics {grDevices} | R Documentation |
Records arbitrary code on the graphics engine display list. Useful for encapsulating calculations with graphical output that depends on the calculations. Intended only for expert use.
recordGraphics(expr, list, env)
expr |
object of mode expression or call or
an “unevaluated expression”. |
list |
a list defining the environment in which expr is to
be evaluated. |
env |
An environment specifying
where R looks for objects not found in
envir . |
The code in expr
is evaluated in an environment constructed
from list
, with env
as the parent of that environment.
All three arguments are saved on the graphics engine display list so that on a device resize or copying between devices, the original evaluation environment can be recreated and the code can be reevaluated to reproduce the graphical output.
The value from evaluating expr
.
This function is not intended for general use. Incorrect or improper use of this function could lead to unintended and/or undesirable results.
An example of acceptable use is querying the current state of a graphics device or graphics system setting and then calling a graphics function.
An example of improper use would be calling the assign
function
to performing assignments in the
global environment.
plot(1:10) # This rectangle remains 1inch wide when the device is resized recordGraphics( { rect(4, 2, 4 + diff(par("usr")[1:2])/par("pin")[1], 3) }, list(), getNamespace("graphics"))