Read a target's return value from its file in
_targets/objects/
. For dynamic files (i.e. format = "file"
)
the paths are returned.
Usage
tar_read(
name,
branches = NULL,
meta = tar_meta(store = store),
store = targets::tar_config_get("store")
)
Arguments
- name
Symbol, name of the target to read.
- branches
Integer of indices of the branches to load if the target is a pattern.
- meta
Data frame of metadata from
tar_meta()
.tar_read()
with the default arguments can be inefficient for large pipelines because all the metadata is stored in a single file. However, if you calltar_meta()
beforehand and supply it to themeta
argument, then successive calls totar_read()
may run much faster.- store
Character of length 1, path to the
targets
data store. Defaults totar_config_get("store")
, which in turn defaults to_targets/
. When you set this argument, the value oftar_config_get("store")
is temporarily changed for the current function call. Seetar_config_get()
andtar_config_set()
for details about how to set the data store path persistently for a project.
Value
The target's return value from its file in
_targets/objects/
, or the paths to the custom files and directories
if format = "file"
was set.
Limited scope
tar_read()
and tar_load()
are only for exploratory analysis and literate programming,
and tar_read_raw()
and tar_load_raw()
are only
for exploratory analysis. targets
automatically
loads the correct dependencies into memory when the pipeline
is running, so invoking these functions
from inside a target is rarely advisable.
See also
Other data:
tar_load_everything()
,
tar_load_raw()
,
tar_load()
,
tar_meta()
,
tar_objects()
,
tar_pid()
,
tar_process()
,
tar_read_raw()
Examples
if (identical(Sys.getenv("TAR_EXAMPLES"), "true")) {
tar_dir({ # tar_dir() runs code from a temporary directory.
tar_script(list(tar_target(x, 1 + 1)), ask = FALSE)
tar_make()
tar_read(x)
})
}