Reads the file with read_vc().
Then verifies that every variable listed in variables is present in the
data.frame.
verify_vc(file, root, variables)the name of the git2rdata object. Git2rdata objects cannot
have dots in their name. The name may include a relative path. file is a
path relative to the root.
Note that file must point to a location within root.
The root of a project. Can be a file path or a git-repository.
Defaults to the current working directory (".").
a character vector with variable names.
Other storage:
list_data(),
prune_meta(),
read_vc(),
relabel(),
rename_variable(),
rm_data(),
write_vc()