ww_comm_write: Global Writing Functions

In pbdMPI: R Interface to MPI for HPC Clusters (Programming with Big Data Project)

Global Writing Functions

Description

These functions are global writing applying on distributed data for all ranks.

Usage

comm.write(x, file = "data", ncolumns = if(is.character(x)) 1 else 5,
           append = FALSE, sep = " ", comm = .pbd_env$SPMD.CT$comm)
comm.write.table(x, file = "", append = FALSE, quote = TRUE, sep = " ",
                 eol = "\n", na = "NA", dec = ".", row.names = TRUE,
                 col.names = TRUE, qmethod = c("escape", "double"),
                 fileEncoding = "", comm = .pbd_env$SPMD.CT$comm)

comm.write.csv(..., comm = .pbd_env$SPMD.CT$comm)
comm.write.csv2(..., comm = .pbd_env$SPMD.CT$comm)

Arguments

x	as in write() or write.table().
file	as in write() or write.table().
ncolumns	as in write*().
append	as in write*().
sep	as in write*().
quote	as in write*().
eol	as in write*().
na	as in write*().
dec	as in write*().
row.names	as in write*().
col.names	as in write*().
qmethod	as in write*().
fileEncoding	as in write*().
...	as in write*().
comm	a communicator number.

Details

These functions will apply write*() locally and sequentially from rank 0, 1, 2, ...

By default, rank 0 makes the file, and rest of ranks append the data.

Value

A file 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() and comm.read.table()

Examples

## Not run: 
### 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))
if(comm.size() != 2){
  comm.cat(\"2 processors are requried.\n\", quiet = TRUE)
  finalize()
}

### Examples.
comm.write((1:5) + comm.rank(), file = \"test.txt\")

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

## End(Not run)

pbdMPI documentation built on Sept. 10, 2023, 5:06 p.m.