Methods of Retrieving Datasets
Most of the datasets on this site are in the S
dumpdata
format (file suffix of
.sdd
) and R compressed
save()
file format (suffix of
.sav
). Some datasets are available in Excel or ASCII (
csv
) formats.
- To manually download and install a dataset, right click on a file to save it to a temporary disk location, e.g., into a directory such as
\windows\temp
or /tmp
- In S-Plus you can import the datasets using the
File ... Import ... S-Plus Transport File
dialog
- Alternatively, use the S-Plus or R command
data.restore('/mydir/file.sdd')
- In
R
, data.restore
is found in the foreign
package, but the binary save
files are much better to use.
- If you have issued
library(Hmisc)
in R or S-Plus you can download and load()
a dataset by just typing getHdata(dataset name)
. To list available dataset names just type getHdata()
. Type ?getHdata
to see other options including ones to browse a dataset's html(contents())
file or its description file (if available) on our web site. Here's an example:
getHdata(prostate)
attach(prostate) ...
If using S-Plus, your system does not have the
wget
executable you must install it for
getHdata
or
download.file
to work. Windows users may obtain
wget.exe
here. Download to a temp file, unzip, and put
wget.exe
in the same directory in which Windows stores
ftp.exe
.
- In S-Plus 5 or later you will need to run imported data frames through the
Hmisc
library's cleanup.import
function if not using getHdata
, e.g., pbc <- cleanup.import(pbc)
to remove object classes that are not allowed in Version 4 of the S language due to its inability to handle multiple inheritance. If using .sdd
files in R
you may want to also run the files through cleanup.import
to store them more efficiently (save
files are already stored efficiently). When using getHdata
in S-Plus it will automatically run cleanup.import
for you.
- In R you can also
load()
a dataset directly from the web using loadURL('http://biostat.mc.vanderbilt.edu/...foo.sav')
.
- It is best to use the datasets with the
Hmisc
library in effect. Among other things, this will allow you to use the Hmisc describe
and contents
functions to obtain documentation about the variables.