I have frequently noticed a strange effect when using the progress bar in a loop, that the console will sometimes be cleared. Whatever was printed before will then be inaccessible, which can be annoying when I want to check the progress and possible issues in a long script. It seems to be an intermittent problem, so it could also be related to my computer or other software running. I have had this issue in several R versions, and managed to provoke it in 3.2.2 with the following: testit <- function(x = 100, ...) { pb <- txtProgressBar(0, x, ...) for(i in 0:x) {Sys.sleep(0.1); setTxtProgressBar(pb, i)} Sys.sleep(4) close(pb) print(1:x) print(1:x) print(1:x) print(length(x)) } for (i in 1:1000) { testit(style = 3) } The printing is just to fill up the console quicker, as the clearing seems to occur more frequent then. However, the loop above can sometimes call testit 5-30 times before the console is cleared again. In my real script the console is usually cleared more frequent. With x = 10 above, it seems not to clear the console, at least not for a long time. Does anyone have a clue why this happens, or if something can be done to prevent it? Is it reproducible, or something that only bothers me? Thanks, Jon BTW: > sessionInfo() R version 3.2.2 (2015-08-14) Platform: x86_64-w64-mingw32/x64 (64-bit) Running under: Windows 8 x64 (build 9200) locale: [1] LC_COLLATE=English_United States.1252 [2] LC_CTYPE=English_United States.1252 [3] LC_MONETARY=English_United States.1252 [4] LC_NUMERIC=C [5] LC_TIME=English_United States.1252 attached base packages: [1] stats graphics grDevices utils datasets methods base -- Jon Olav Sk?ien Joint Research Centre - European Commission Institute for Environment and Sustainability (IES) Climate Risk Management Unit Via Fermi 2749, TP 100-01, I-21027 Ispra (VA), ITALY jon.skoien at jrc.ec.europa.eu Tel: +39 0332 789205 Disclaimer: Views expressed in this email are those of the individual and do not necessarily represent official views of the European Commission.