Avoiding a "stack" stack "is a complete mistake when sink () is used to grab messages in a foreach loop

Question

To view console messages displayed by a function running in a loop foreach(), I followed this guy’s advice and added a sink()calls like this:

   library(foreach)    
   library(doMC)
   cores <- detectCores()
   registerDoMC(cores)

   X <- foreach(i=1:100) %dopar%{
   sink("./out/log.branchpies.txt", append=TRUE)
   cat(paste("\n","Starting iteration",i,"\n"), append=TRUE)
   myFunction(data, argument1="foo", argument2="bar")
   }

However, at iteration 77, I received the error message "sink stack is full". There are answers to questions about avoiding this error when using for-loops, but not foreach. What is the best way to write hidden foreach output to a file?

Answer 1

This runs without errors on my Mac:

library(foreach)    
library(doMC)
cores <- detectCores()
registerDoMC(cores)

X <- foreach(i=1:100) %dopar%{
  sink("log.branchpies.txt", append=TRUE)
  cat(paste("\n","Starting iteration",i,"\n"))
  sink() #end diversion of output
  rnorm(i*1e4)
}

This is better:

library(foreach)    
library(doMC)
cores <- detectCores()
registerDoMC(cores)
sink("log.branchpies.txt", append=TRUE)
X <- foreach(i=1:100) %dopar%{
  cat(paste("\n","Starting iteration",i,"\n"))
    rnorm(i*1e4)
}
sink() #end diversion of output

:

library(foreach)    
library(doMC)
cores <- detectCores()
registerDoMC(cores)

X <- foreach(i=1:100) %dopar%{
  cat(paste("\n","Starting iteration",i,"\n"), 
       file="log.branchpies.txt", append=TRUE)
  rnorm(i*1e4)
}

Answer 2

, . cat , , :

cat(..., file="log.txt", append=TRUE)

, -, cat:

catf <- function(..., file="log.txt", append=TRUE){
  cat(..., file=file, append=append)
}

, , foreach, - :

library(foreach)    
library(doMC)
cores <- detectCores()
registerDoMC(cores)

X <- foreach(i=1:100) %dopar%{
  catf(paste("\n","Starting iteration",i,"\n"))
  rnorm(i*1e4)
}

, !

Answer 3

sink() for reset, , .