R devel - Jul 2010 - How to use mpi.allreduce() in Rmpi?

Hi everybody!

I have the next code which makes a reduction of the *a *variable in two
slaves, using the Rmpi package.

library(Rmpi)

mpi.spawn.Rslaves(nslaves=2)

reduc<-function(){
  a<-mpi.comm.rank()+2
  mpi.reduce(a,type=2, op="prod")
  return(paste("a=",a))
}

mpi.bcast.Robj2slave(reduc)
mpi.remote.exec(reduc())

cat("Product: ")
mpi.reduce(1,op="prod")


mpi.close.Rslaves()


I want to use the function mpi.allreduce() instead of mpi.reduce(), so
slaves should receive the value of the reduction. I don't know how to do it
and the avaliable documentation is very small and i'm starting with Rmpi. I
also tried with the next two changes but nothing:


library(Rmpi)

mpi.spawn.Rslaves(nslaves=2)

reduc<-function(){
  a<-mpi.comm.rank()+2
  mpi.reduce(a,type=2, op="prod")
  return(paste("a=",a))
}

mpi.bcast.Robj2slave(reduc)
mpi.remote.exec(reduc())

cat("Product: ")
mpi.allreduce(1,op="prod")


mpi.close.Rslaves()



and



library(Rmpi)

mpi.spawn.Rslaves(nslaves=2)

reduc<-function(){
  a<-mpi.comm.rank()+2
  mpi.allreduce(a,type=2, op="prod")
  return(paste("a=",a))
}

mpi.bcast.Robj2slave(reduc)
mpi.remote.exec(reduc())

cat("Product: ")
mpi.allreduce(1,op="prod")


mpi.close.Rslaves()

Could somebody help me?

Thanks a lot in advance for your help !*
*

	[[alternative HTML version deleted]]

Hi everybody!

I have the next code which makes a reduction of the *a *variable in two
slaves, using the Rmpi package.

library(Rmpi)

#get the slaves
mpi.spawn.Rslaves(nslaves=2)

#slaves will execute this function
reduc<-function(){
  a<-mpi.comm.rank()+2
  mpi.reduce(a,type=2, op="prod")
  return(paste("a=",a))
}

#send function
mpi.bcast.Robj2slave(reduc)

#execute function by slaves
mpi.remote.exec(reduc())

#get reduction
cat("Product: ")
mpi.reduce(1,op="prod")


mpi.close.Rslaves()


I want to use the function mpi.allreduce() instead of mpi.reduce(), so
slaves should receive the value of the reduction. I don't know how to do it
and the avaliable documentation is very small and i'm starting with Rmpi. I
also tried with the next two changes but nothing:


library(Rmpi)

mpi.spawn.Rslaves(nslaves=2)

reduc<-function(){
  a<-mpi.comm.rank()+2
  mpi.reduce(a,type=2, op="prod")
  return(paste("a=",a))
}

mpi.bcast.Robj2slave(reduc)
mpi.remote.exec(reduc())

cat("Product: ")
mpi.allreduce(1,op="prod")


mpi.close.Rslaves()



and



library(Rmpi)

mpi.spawn.Rslaves(nslaves=2)

reduc<-function(){
  a<-mpi.comm.rank()+2
  mpi.allreduce(a,type=2, op="prod")
  return(paste("a=",a))
}

mpi.bcast.Robj2slave(reduc)
mpi.remote.exec(reduc())

cat("Product: ")
mpi.allreduce(1,op="prod")


mpi.close.Rslaves()

Could somebody help me?

Thanks a lot in advance for your help !*
*

	[[alternative HTML version deleted]]