data {base} | R Documentation |
data
loads a data set or lists (via show.data
)
the available data sets.
data(..., list = character(0), package = .packages(), lib.loc = .lib.loc) show.data(package = .packages(), lib.loc = .lib.loc)
... |
a sequence of names or character strings. |
list |
a character vector. |
package |
a name or character vector giving the packages to
look into for data sets. By default, all packages in the search
path are used, then the data directory (if present) of the
current working directory. |
lib.loc |
a character vector of directory names of R libraries. Defaults to all libraries currently known. If the default is used, the loaded packages are searched before the libraries. |
Currently, four formats of data files are supported:
load()
ed.
source()
d in, with the R working directory changed
temporarily to the directory containing the respective file.
read.table(..., header = TRUE)
, and hence result in
a data frame.
read.table(..., header = TRUE, sep = ";")
,
and also result in a data frame.
The data sets to be loaded can be specified as a sequence of names or
character strings, or as the character vector list
, or as both.
If no data sets are specified or show.data
is called directly,
the available data sets are displayed.
If no data sets are specified, data
calls show.data
.
show.data
looks for a file `00Index' in a `data'
directory of each specified package, and uses these files to prepare
a listing. If there is a `data' area but no index a warning is
given: such packages are incomplete.
If lib.loc
is not specified, the datasets are searched for
amongst those packages already loaded, followed by the `data'
directory (if any) of the current working directory and then packages
in the specified libraries. If lib.loc
is
specified, packages are searched for in the specified libraries, even if
they are already loaded from another library.
To just look in the `data' directory of the current working
directory, set package = NULL
.
data()
returns a character vector of all data sets specified,
an empty character vector if none were specified.
The data files can be many small files. On some file systems it is desirable to save space, and the files in the `data' directory of an installed package can be zipped up as a zip archive `Rdata.zip'. You will need to provide a single-column file `filelist' of file names in that directory.
One can take advantage of the search order and the fact that a
`.R' file will change directory. If raw data are stored in
`mydata.txt' then one can set up `mydata.R' to read
`mydata.txt' and pre-process it, e.g. using transform
. For
instance one can convert numeric vectors to factors with the
appropriate labels.
Thus, the `.R' file can effectively contain a metadata
specification for the plaintext formats.
help
for obtaining documentation on data sets.
data() # list all available data sets data(package = base) # list the data sets in the base package data(USArrests, "VADeaths") # load the data sets `USArrests' and `VADeaths' help(USArrests) # give information on data set `USArrests'