This function checks the "rgl.useNULL" option if present, or the RGL_USE_NULL environment variable if it is not. If the value is TRUE or a string which matches “yes” or “true” in a case-insensitive test, TRUE is returned.

rgl.useNULL()

Note

This function is checked by the initialization code when the rgl package is loaded. Thus if you want to run RGL on a system where there is no graphics support, you should run options(rgl.useNULL = TRUE) or set the environment variable RGL_USE_NULL=TRUE *before* calling library(rgl) (or other code that loads rgl), and it will not fail in its attempt at initialization.

Value

A logical value indicating the current default for use of the null device.

Author

Duncan Murdoch

See also

Examples

rgl.useNULL()
#> [1] FALSE