Where generated coefficient tables are kept between sessions

The mesh-free weighted-L2 tables are shipped with the package, but a table for a particular spectral interval (see rspde.wl2.table() and the kappa_ref argument of matern.operators()) has to be computed, which takes of the order of a second. Within a session such tables are cached in memory. Enabling this cache stores them on disk as well, so that a second session, or a script run again, finds them instead of refitting.

The cache is off by default: a package should not write outside the session temporary directory unless asked to. Calling rspde.cache(TRUE) is that request, and creates the directory. The environment variable RSPDE_CACHE_DIR sets it for non-interactive use, for instance from .Renviron.

Cached files are organised by package version, so upgrading the package does not read tables produced by an older fit. Within a development version, clear the cache after changing anything that affects the coefficients.

Usage

rspde.cache(dir, clear = FALSE)

Arguments

dir

TRUE to enable the cache at the standard location for this package, tools::R_user_dir("rSPDE", "cache"); FALSE to disable it; a path to use that directory instead; or missing to query the current setting.

clear

Delete the tables that are currently stored?

Value

The cache directory, or NULL if the cache is off, invisibly when called for its effect.

See also

rspde.wl2.table(), matern.operators()

Examples

rspde.cache()
#> NULL
if (FALSE) { # \dontrun{
rspde.cache(TRUE) # store generated tables between sessions
rspde.cache(clear = TRUE) # throw away what is stored
rspde.cache(FALSE)
} # }