抑制function的output

Question

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

Answer 1

It isn't clear why you want to do this without sink , but you can wrap any commands in the invisible() function and it will suppress the output. For instance:

1:10 # prints output
invisible(1:10) # hides it

Otherwise, you can always combine things into one line with a semicolon and parentheses:

{ sink("/dev/null"); ....; sink(); }

Answer 2

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')
> 

Answer 3

The following function should do what you want exactly:

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

Answer 4

R 只会自动打印未分配表达式的输出，因此只需将apply<\/code>的结果分配给一个变量，它就不会被打印出来。

"

Answer 5

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

Answer 6

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

Answer 7

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<\/code> package

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

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

Answer 8

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

Answer 9

If you're wondering how to suppress a warning() you can use suppressWarnings() like so:

suppressWarnings(warning("hi"))

Whereas these two will still show the warning:

invisible(warning("Hi"))
# shows 'Hi'

capture.output(warning("Hi"), file='NUL')
# shows 'Hi'

Answer 10

for the return(something) part inside an R function:

return(invisible(something))  

works ok

invisible(return(something))

does not work at all

Answer 11

Here is a version that is robust to errors in the code to be shushed:

quietly <- function(x) {
  sink("/dev/null") # on Windows (?) instead use `sink("NUL")`
  tryCatch(suppressMessages(x), finally = sink())
}

• This is based directly on the accepted answer , for which thanks.
• But it avoids leaving output silenced if an error occurs in the quieted code.