R is an open source programming language designed
for statistical computing. In contrast with SQL, which most often operates
on rows of table data, R is more suited to processing table data by columns.
For example, it is straightforward in R to select a range of columns from
a table and apply a statistical function to each of the values. R also
includes a graphical component which allows table data to be plotted using
a wide variety of graphs and charts.
In LiveCompare, R is implemented using the
Execute R action. This is similar
to the Execute SQL action: it runs a set of R statements against one or
more source tables to produce a result table. However the column values
from each of the source tables are immediately available to the R script
as vectors. The Execute R action also supports other input and output
types.
LiveCompare includes a number of sample R scripts,
stored in the R script repository.
These may be called directly using the Execute R action.
LiveCompare workflows may include Image
datasets, which are used to store the graphs and charts generated
by the Execute R action. The graphs and charts may be displayed directly
in a workflow, or included in Dashboard
reports.
The Execute R action requires that R is installed
on your LiveCompare server as described in the LiveCompare Installation
and Configuration Guide. If you are running LiveCompare from a client
machine, you may wish to install R locally in order to try out some of
the examples presented in the Help.
The internet includes a large number of R resources,
in particular the R project site at http://www.r-project.org. This site includes download
links for R and its associated packages, as well as links to documentation
and frequently asked questions. In particular, the following manual in
HTML format provides an introduction to R.