Attach: Attach object cache
Description
Place a stored object cache one the search path, or change the position
of such a cache already on the search path.Usage
Attach(lib = Sys.getenv("R_LOCAL_CACHE", unset = ".R_Cache"),
lib.loc = Sys.getenv("R_LOCAL_LIB_LOC", unset = "."),
pos = 2, uniquely = TRUE, readonly = FALSE, ...)
AttachData(...)
AttachUtils(...)
Arguments
lib
The name of the cache directory from which items are to be
removed. May be given as a character string, or as a name,
(i.e. without quotes) for convenience. The default is as follows:
- For
Attach
, the value of theR
lib.loc
The enclosing directory where the cache directory is to be found.
The default is as follows:
- For
Attach
, the value of theR
environment
variableR_LOCAL_LIB_LOC
, or the current working directory
if unse
pos
The position on the search path where the object cache is to be
placed, or the new position if the cache is already on the search
path.
uniquely
Logical. Are multiple copies of the same cache on the search path to
be disallowed? If TRUE
, a single copy only is left on the
search path.
readonly
Logical. If TRUE
modifications to the objects in the cache
are prevented.
...
Extra arguments to be passed on to internal SOAR
functions.
Presently unused.
Value
- Nothing of interest. The function is used solely for its side-effect on
the search path
Details
An existing object cache is attached to the search path. If the
object cache directory, file.path(lib.loc, lib)
, currently does
not exist a warning is issued to that effect, but also advising that
the directory will be created when an object is to be Store
d
there.Examples
## change default cache, keeping any previous setting
oldLC <- Sys.getenv("R_LOCAL_CACHE", unset = ".R_Cache")
Sys.setenv(R_LOCAL_CACHE=".R_Test")
## generate some dummy data
dummy <- rnorm(100)
mn <- mean(dummy)
va <- var(dummy)
Attach() # may give warning
## store it in the stored object cache
Store(dummy, mn, va)
Search()
Attach(pos=3) # change to pos=3
Search()
Objects()
Remove(mn, va)
Objects()
Remove(Objects()) # empty the cache
detach(".R_Test") # remove from search path
Sys.setenv(R_LOCAL_CACHE=oldLC) # restore normal default