global writing {pbdMPI}

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)