Rmpi: mpi.gather.Robj – R documentation

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mpi.gather.Robj

Extentions of MPI\_Gather and MPI\_Allgather APIs

Description

mpi.gather.Robj gathers each member's object to the member specified by the argument root. The root member receives the objects as a list. mpi.allgather.Robj is the same as mpi.gather.Robj except that all members receive the result instead of just the root.

Usage

mpi.gather.Robj(obj=NULL, root = 0, comm = 1, ...)

mpi.allgather.Robj(obj=NULL, comm = 1)

Arguments

`obj`	data to be gathered. Could be different type.
`root`	rank of the gather
`comm`	a communicator number
`...`	optional arugments to `sapply`.

Details

Since sapply is used to gather all results, its default option "simplify=TRUE" is to simplify outputs. In some situations, this option is not desirable. Using "simplify=FALSE" as in the place of ... will tell sapply not to simplify and a list of outputs will be returned.

Value

For mpi.gather.Robj, it returns a list, the gathered message for the root member. For mpi.allgatherv.Robj, it returns a list, the gathered message for all members.

Author(s)

Hao Yu and Wei Xia

References

https://www.open-mpi.org/

Examples

#Assume that there are some slaves running
mpi.bcast.cmd(id<-mpi.comm.rank())
mpi.bcast.cmd(x<-rnorm(id))
mpi.bcast.cmd(mpi.gather.Robj(x))
x<-"test mpi.gather.Robj"
mpi.gather.Robj(x)

mpi.bcast.cmd(obj<-rnorm(id+10))
mpi.bcast.cmd(nn<-mpi.allgather.Robj(obj))
obj<-rnorm(5)
mpi.allgather.Robj(obj)
mpi.remote.exec(nn)

Rmpi

Interface (Wrapper) to MPI (Message-Passing Interface)

v0.6-9.1

GPL (>= 2)

Authors

Hao Yu [aut]

Initial release

2021-02-22