= R-MPI =

== 1.What is R-MPI ==
----
== 2.Software Requirement ==
 * MPI implements
  * mpich2, mpich, [http://www.lam-mpi.org/ LAM/MPI] (7.0.2 or higher)
   * For mpich2 installation, please reference [wiki:MPICH2_Install here]
  * OpenMPI may causes some problem, not for sure.
 * R (2.0.0 or higher)
  * Assuming that your system is ubuntu or you got apt-get commands, you can just install R by :
{{{
root@client-01:~# apt-get install r-base-core
}}}
 * gcc-4.2
  * As previous step, you should install gcc-4.2 by :
{{{
root@client-01:~# apt-get install gcc-4.2
}}}
  * If you want use lower version of gcc, please link the gcc-4.2 to your location of your gcc compiler. Such as:
{{{
root@client01:~# ln -s /usr/bin/gcc /usr/bin/gcc-4.2
}}}
----
== 3.Install Rmpi ==
 * Download for Rmpi from [http://www.stats.uwo.ca/faculty/yu/Rmpi/ here].
   The latest version is 0.5-5.
{{{
root@client-01:/opt# wget http://www.stats.uwo.ca/faculty/yu/Rmpi/download/linux/Rmpi_0.5-5.tar.gz
}}}
 * Assuming that your system have installed R, gcc-4.2 and any one of MPI implements already.
   Then we can start to install Rmpi as follows
{{{
root@client-01:/opt# R CMD INSTALL Rmpi_0.5-5.tar.gz --configure-args=--with-mpi=/opt/mpich2
}}}
 * Rmpi have been installed successfully so far.
----
== 4.Test for Rmpi ==
 * At first, you need to start mpi at Master node (such as client-01).[[BR]]
   For example, mpich2,
{{{
root@client-01:/opt# mpdboot -n 3 -f /root/mpich2-1.0.7rc1/mpd.hosts
root@client-01:/opt# mpdtrace
client-01
client-03
client-02
}}}
 * Test for [http://ace.acadiau.ca/math/ACMMaC/Rmpi/task_pull.R example program][[BR]]
   '''Notice''' that this example has a plot in it so trying it in X-windows.
{{{
root@client-01:/opt# wget http://ace.acadiau.ca/math/ACMMaC/Rmpi/task_pull.R
root@client-01:/opt# mpirun -np 1 R --slave CMD BATCH task_pull.R
}}}
 * If success, there will be two files generated out, they are Rplots.ps, task_pull.Rout.[[BR]]

 * Simple check of R-MPI environment 
   * Reference code from [http://ace.acadiau.ca/math/ACMMaC/Rmpi/sample.html Rmpi Sample Program], Acadia Centre for Mathematical Modelling and Computation
{{{
# R
> if (!is.loaded("mpi_initialize")) {
+ library("Rmpi")
+ }
}}}
 * If you did not install LAM/MPI, you should see this message
{{{
> if (!is.loaded("mpi_initialize")) {
+ library("Rmpi")
+ }

        LAM/MPI runtime environment is not operating.
        Starting LAM/MPI runtime environment.
}}}
 * For more test program, please reference [http://www.math.ncu.edu.tw/~chenwc/R_note/index.php?item=Rmpi R_note].



----
== 5.Reference ==

 * [http://www.r-project.org/ The R Project Offical Website]
 * [http://www.stats.uwo.ca/faculty/yu/Rmpi/ Rmpi Project Offical Website]
 * [http://www.statistik.uni-dortmund.de/useR-2008/ The R User Conference 2008]
 * [http://cran.r-project.org/web/packages/Rmpi/index.html Rmpi: Interface (Wrapper) to MPI (Message-Passing Interface)]
 * [http://packages.debian.org/stable/math/r-cran-rmpi Debian Rmpi Package]

 * [http://www.eyaoo.net/R/ Chinese Documentation for GNU R] - 中文手冊