prism_check: Helper function to check if files already exist
Description
check if files exist
Usage
prism_check(prismfiles, lgl = FALSE)
Arguments
prismfiles
a list of full paths for prism files
lgl
TRUE returns a logical vector indicating those
not yet downloaded; FALSE
returns the file names that are not yet downloaded.
Value
a character vector of file names that are not yet downloaded
or a logical vector indication those not yet downloaded..