To call R from within Matlab, you will need to have R compiled as a
shared library.  This needs to be done when compiling R from source
(or via one of the binary distributions that have support for this.)

Download the R source from cran.r-project.org.

  tar zxf R-2.0.0.tar.gz
  ./configure --enable-R-shlib
  make

Then, ensure that this version of R is in your path.
Either install it or put the bin/ directory in your
path.


Install the RMatlab package as a regular R package.

 R CMD INSTALL RMatlab.


================================================================

Running RMatlab.

Tell matlab to look for MEX files in
the directory <R package install directory>/RMatlab/libs
Use the MATLABPATH environment variable for this.

Add $R_HOME/lib/ to the LD_LIBRARY_PATH environment variable
so that the operating system can find the libR.so file
at run-time.

The scripts  RMatlab.csh (tcsh or csh shells) or RMatlab.sh (Bourne (sh) or Bash (bash) shells)
in the scripts/ directory of the _installed_ R package will set things correctly
for you. Just source them into your shell:
  source RMatlab.csh 
or
  . RMatlab.sh

depending on which type of shell you are using.




Set the location of the R installation so that the R engine
can find its code.

  setenv R_HOME `R RHOME`

Set the environment variable LD_LIBRARY_PATH to 

   setenv LD_LIBRARY_PATH $R_HOME/lib

(or $R_HOME/bin for versions of R pre 2.0.0)


Initialize the R engine.

   x = initializeR({'Rmatlab' '--no-save', '--silent'})

Note that the arguments are given using a Matlab cell ({})
rather than a matrix. Any number of recognized arguments
can be passed to R just as one would invoke it from the
command line.



Call a simple R function.

  o = callR('date')

   
  o = callR('rnorm', 10)

    # generate 50 Normal deviates from N(100, 1)
  o = callR('rnorm', 50, 100)

    # Poisson random variable.
  o = callR('rpois', 50, 3)




Calling Matlab from within R.

First, set the LD_LIBRARY_PATH environment
variable to find the relevant Matlab shared libraries.
On Linux, this is 
 <Matlab installation>/bin/glnx86

Now, run R.

 > library(RMatlab)

 > .MatlabInit()

 > .Matlab('magic', 3)


To call Matlab from R that is already within a Matlab session
(i.e. starting from Matlab and calling an R function that itself
calls Matlab), you can use

  .MatlabMexCall

rather than .Matlab.
In the future, there will be numerous other 
functions that one can access and the package
will automatically understand which version to
use.



DTL (Nov, 2 2004)