Testing availability of optional package, its version, and extra global default. This function is used internally. It is exported and documented because user can control behavior of the function by global option.
use.package( package, version = "1.9.8"[package == "data.table"], use = getOption("h2o.use.data.table", TRUE)[package == "data.table"] )
| package | character scalar name of a package that we Suggests or Enhances on. |
|---|---|
| version | character scalar required version of a package. |
| use | logical scalar, extra escape option, to be used as global option. |
We use this function to control csv read/write with optional data.table package.
Currently data.table is enabled by default for some operations, to disable it set options("h2o.use.data.table"=FALSE).
It is possible to control just fread or fwrite with options("h2o.fread"=FALSE, "h2o.fwrite"=FALSE).
h2o.fread and h2o.fwrite options are not handled in this function but next to fread and fwrite calls.
as.h2o.data.frame, as.data.frame.H2OFrame
op <- options("h2o.use.data.table" = TRUE) if (use.package("data.table")) { cat("optional package data.table 1.9.8+ is available\n") } else { cat("optional package data.table 1.9.8+ is not available\n") } options(op)