Greetings,

I am a novice user of Rmpi package.  My machine is a redhat linux machine.
I have installed Rmpi package on R v2.10.1 recently.  I have also installed
openMPI v1.4.3.

Here’s a tutorial I tried:

   > library( Rmpi )
   >
   > mpi.spawn.Rslaves( nslaves=4 )
           4 slaves are spawned successfully. 0 failed.
   master (rank 0, comm 1) of size 5 is running on: vixen
   slave1 (rank 1, comm 1) of size 5 is running on: vixen
   slave2 (rank 2, comm 1) of size 5 is running on: vixen
   slave3 (rank 3, comm 1) of size 5 is running on: vixen
   slave4 (rank 4, comm 1) of size 5 is running on: vixen
   >
   > mpi.remote.exec( paste('I am ', mpi.comm.rank(), 'of ',
   +                        mpi.comm.size() ) )
   $slave1
   [1] "I am  1 of  5"

   $slave2
   [1] "I am  2 of  5"

   $slave3
   [1] "I am  3 of  5"

   $slave4
   [1] "I am  4 of  5"

   >
   > mpi.close.Rslaves()
   [1] 1
   >
   > mpi.quit()

This looks OK, but all “slaves” are running on the same machine, albeit different
core, as the “master.”  I would like to spawn the slaves on a different machine on
the network.  According to the api document, mpi.spawn.Rslaves() has an argument
hosts: (NULL or LAM node number to specify where R slaves to be spawned.)  I am
using openMpi, not LAM Mpi.  Can somebody please tell me how I can get ‘hosts’
for mpi.spawn.Rslaves()?

Also, when I issue:
   > lamhosts()
I get:
   sh: lamnodes: command not found
   <NA> <NA>
      0   -1

I think this is because lamhosts() is defined as:
   function ()
   {
       hosts <- system("lamnodes C -c -n", TRUE)
       base <- character(0)
       for (host in hosts) base <- c(base, unlist(strsplit(host,
           "\\."))[1])
       nn <- 0:(length(hosts) - 1)
       names(nn) <- base
      nn
   }

I don’t think lamnodes exits in opne Mpi.  Does this mean I can’t
get Rmpi to work with open Mpi?  Does anybody have some work-around?

Thank you in advance for your help.

Regards,

Tena Sakai
tsakai@gallo.ucsf.edu

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