[r] Suppress output of a function

I'm looking to suppress the output of one command (in this case, the apply function).

Is it possible to do this without using sink()? I've found the described solution below, but would like to do this in one line if possible.

How to suppress output

This question is related to r

The answer is


In case anyone's arriving here looking for a solution applicable to RMarkdown, this will suppress all output:

```{r error=FALSE, warning=FALSE, message=FALSE}
invisible({capture.output({

# Your code goes here
2 * 2
# etc
# etc


})})
```

The code will run, but the output will not be printed to the HTML document


Making Hadley's comment to an answer (hope to make it better visible). Use of apply family without printing is possible with use of the plyr package

x <- 1:2
lapply(x, function(x) x + 1)
#> [[1]]
#> [1] 2
#> 
#> [[2]]
#> [1] 3

plyr::l_ply(x, function(x) x + 1)

Created on 2020-05-19 by the reprex package (v0.3.0)


invisible(cat("Dataset: ", dataset, fill = TRUE))
invisible(cat(" Width: " ,width, fill = TRUE))
invisible(cat(" Bin1:  " ,bin1interval, fill = TRUE))
invisible(cat(" Bin2:  " ,bin2interval, fill = TRUE))
invisible(cat(" Bin3:  " ,bin3interval, fill = TRUE))

produces output without NULL at the end of the line or on the next line

Dataset:  17 19 26 29 31 32 34 45 47 51 52 59 60 62 63
Width:  15.33333

Bin1:   17 32.33333
Bin2:   32.33333 47.66667
Bin3:   47.66667 63

R only automatically prints the output of unassigned expressions, so just assign the result of the apply to a variable, and it won't get printed.


The following function should do what you want exactly:

hush=function(code){
  sink("NUL") # use /dev/null in UNIX
  tmp = code
  sink()
  return(tmp)
}

For example with the function here:

foo=function(){
  print("BAR!")
  return(42)
}

running

x = hush(foo())

Will assign 42 to x but will not print "BAR!" to STDOUT

Note than in a UNIX OS you will need to replace "NUL" with "/dev/null"


Use the capture.output() function. It works very much like a one-off sink() and unlike invisible(), it can suppress more than just print messages. Set the file argument to /dev/null on UNIX or NUL on windows. For example, considering Dirk's note:

> invisible(cat("Hi\n"))
Hi

> capture.output( cat("Hi\n"), file='NUL')
> 

you can use 'capture.output' like below. This allows you to use the data later:

log <- capture.output({
  test <- CensReg.SMN(cc=cc,x=x,y=y, nu=NULL, type="Normal")
})

test$betas