How to output text in the R console without creating new lines?
RNewlineRstudioOutput FormattingR Problem Overview
I would like to output a progress indicator during my lengthy running algorithms. I can easily "bubble up" a progress value from within my algorithm (e.g. via invoking a provided function callback specifically for this purpose), but the difficulty is in the actual text output process. Every call to print creates a new line, and each prefixed with [1].
Is there a way to print at different moments in time, without introducing line breaks?
To be concrete, I want to achieve an "animation" that would look like the following if observed at two different times.
0%...
...
0%...2%...4%...
R Solutions
Solution 1 - R
Use cat() instead of print():
cat("0%")
cat("..10%")
Outputs:
0%..10%
Solution 2 - R
Bah, Andrie beat me to it by 28 seconds.
> for (i in 1:10) {
+ cat(paste("..", i, ".."))
+ }
.. 1 .... 2 .... 3 .... 4 .... 5 .... 6 .... 7 .... 8 .... 9 .... 10 ..
Solution 3 - R
Maybe you can yse plyr
l_ply(1:4,function(x) x+1,.progress= progress_text(char = '+'),.print=TRUE)
| | 0%[1] 2
|++++++ | 25%[1] 3
|+++++++++++++++ | 50%[1] 4
|++++++++++++++++++++++ | 75%[1] 5
|++++++++++++++++++++++++++++++++ | 100%[1]
Solution 4 - R
If you really need a progress bar as such, use txtProgressBar for console output. Or winProgressBar under Windows for a windowed progress bar.
Solution 5 - R
I believe that you are looking for \r in the cat function like below:
for(i in 1:100) {
cat('\r',
i,
'% |',
rep('=', i / 4),
ifelse(i == 100, '|\n', '>'), sep = '')
Sys.sleep(.1)
}