npRmpi (version 0.60-20)

mpi.dims.create: MPI_Dims_create

Description

mpi.dims.create Create a Cartesian dimension used by mpi.cart.create.

Usage

mpi.dims.create(nnodes, ndims, dims=integer(ndims))

Value

mpi.dims.create returns the dimension vector used by that in mpi.cart.create.

Arguments

nnodes

Number of nodes in a cluster

ndims

Number of dimension in a Cartesian topology

dims

Initial dimension numbers

Author

Hao Yu

Details

The entries in the return value are set to describe a Cartesian grid with ndims dimensions and a total of nnodes nodes. The dimensions are set to be as close to each other as possible, using an appropriate divisibility algorithm. The return value can be constrained by specifying positive number(s) in dims. Only those 0 values in dims are modified by mpi.dims.create.

References

https://www.mpich.org/, https://www.mpich.org/static/docs/latest/www3/

See Also

mpi.cart.create

Examples

if (FALSE) {
## Not run in checks when toggled to dontrun: this MPI utility example is
## intended for manual interactive use.
#What is the dim numbers of 2 dim Cartersian topology under a grid of 36 nodes
mpi.dims.create(36,2)	#return c(6,6)
#Constrained dim numbers
mpi.dims.create(12,2,c(0,4)) #return c(9,4)
}