global as.gbd {pbdMPI}

Global As GBD Function

Description

This function redistributes a regular matrix existed in rank.soure and turns it in a gbd matrix in row blocks.

Usage

comm.as.gbd(X, balance.method = .pbd_env$SPMD.IO$balance.method,
            rank.source = .pbd_env$SPMD.CT$rank.source,
            comm = .pbd_env$SPMD.CT$comm)

Arguments

X

a regular matrix in rank.source and to be redistributed as a gbd.

balance.method

a balance method.

rank.source

a rank of source where elements of x scatter from.

comm

a communicator number.

Details

X matrix in rank.source will be redistributed as a gbd matrix in row blocks.

This function will first set NULL to X if it is not located in rank.source, then called comm.load.balance() to redistributed the one located in rank.source to all other ranks.

Value

A X.gbd will be returned.

Author(s)

Wei-Chen Chen [e-mail], George Ostrouchov, Drew Schmidt, Pragneshkumar Patel, and Hao Yu.

References

Programming with Big Data in R Website: https://pbdr.org/

See Also

comm.load.balance(), comm.read.table() and comm.write.table().

Examples

### Save code in a file "demo.r" and run with 2 processors by
### SHELL> mpiexec -np 2 Rscript demo.r

spmd.code <- "
### Initialize
suppressMessages(library(pbdMPI, quietly = TRUE))

### Examples.
X <- matrix(1:15, ncol = 3)
X.gbd <- comm.as.gbd(X)
comm.print(X.gbd, all.rank = TRUE)

### Finish.
finalize()
"
pbdMPI::execmpi(spmd.code, nranks = 2L)