README for Ra for Windows

Ra is functionally identical to R but provides just-in-time compilation of loops and arithmetic expressions in loops. This usually makes arithmetic in Ra much faster than in R. To find out more about Ra, please see www.milbo.users.sonic.net/ra.

How do I get started with Ra?

To get started with the just-in-time compiler, try

library(jit)
example(jit)

from within Ra.

How does installing Ra affect R?

Installing Ra does not affect your R installation, with two benign exceptions:

the Ra installer creates a new directory bin-ra below R's home directory.
the Ra installer installs the jit package which can be accessed from R like any other package.

After installing Ra, you can carry on using R as before, or you can use Ra. No R files are changed. The installer does not change your PATH. File associations are not changed and still point to R, not Ra.

How do I uninstall Ra?

To uninstall Ra, run Uninstall Ra from the Start|All Programs menu. Uninstalling Ra does not affect R.

Why is the Ra download so small compared to the R download?

Ra piggy-backs on R.

How can I invoke Ra's version of R and Rterm from the command line?

The Ra executables have the same name as name as their R counterparts but are in the bin-ra directory. The Ra installer does not change your PATH. Thus use a batch file containing something like this:
"\Program Files\R\R-x.x.x\bin-ra\Rterm" --quiet --ess %1 %2 %3

Another approach is to manually modify your PATH so \Program Files\R\R-x.x.x\bin-ra is before or replaces \Program Files\R\R-x.x.x\bin.

How can I tell if I'm running Ra and not R?

From within Ra or R, execute version. Under Ra the returned version.string will contain Ra and its version:

R R-VERSION (DATE Ra RA-VERSION)

Also, after loading library(jit), the variable is.ra will be TRUE under Ra and FALSE under R.

Ra says it cannot open the README file. Help?

Under Vista, Ra sometimes issues a message saying it cannot open the README file although it does in fact open it. This is a known issue and is under investigation.

Ra says it cannot save my workspace image. Help?

Under Vista, Ra sometimes reports that it cannot save the the workspace image on quitting. If you are using the GUI interface and get this message after quitting, edit the Ra desktop icon by right clicking on it, selecting "Properties", and changing the "Start In" field to a directory in which you have write permission.

How do I report bugs in Ra?

Try your program under standard R to see if the bug is an R bug, not an Ra specific bug. If it is an R bug, not an Ra bug, then report it as described in the R FAQ. As always, please first read the bugs section in the R FAQ and R for Windows FAQ.

If it is an Ra bug, or if you are not sure if it is an Ra bug, email a report to Stephen Milborrow.

What exactly does the Ra installer do?

The installer installs the two components of Ra:

the Ra executables and DLL which live in the bin-ra directory
the jit package, which lives in its own subdirectory in the library directory just like any other CRAN package.

Ra uses your existing R files where necessary e.g. for packages.

In detail, this is what the Ra installer does, in order:

Check that the version of R needed for the current version of Ra is installed in the standard place. Do this by checking that RHOME\bin and RHOME\bin\Rgui.exe exist. Here, RHOME is the directory where R was installed, typically C:\Program Files\R\R-x.x.x.
Copy the contents of RHOME\bin to RHOME\bin-ra.
Replace Rgui.exe and R.dll in RHOME\ra-bin with Ra versions. Also copy this README file and any files that it references into RHOME\ra-bin.
Create the directory RHOME\library\jit and copy the jit package files into it.
Put Ra icons onto the Task Bar and the Desktop, and adds entries for Ra and Uninstall Ra to Start|All Programs menu|R|Ra.

Additionally, the installer adds a registry entry for use during uninstallation Windows\CurrentVersion\uninstall\Ra_is1.

What exactly does the Ra uninstaller do?

The uninstaller deletes the files it put in the directory RHOME\library\bin-ra. It then deletes the directory itself, but only if it is empty and did not exist before installation of Ra.

The uninstaller does not remove the jit package i.e. it does not delete the directory RHOME\library\jit.

The uninstaller does not change your PATH.