How to be alerted about the ongoing progress of a loop/lapply

loops, r

Solution

It sounds like you're using RGui on Windows. There should be an option in one of the menus to tell it to not buffer the output. Alternatively you could call `flush.console` after every time you print.

lapply(1:1000, function(i){print(i); flush.console()})

Note that this will slow down the code a little bit.

Problem

In `R`, I will sometimes have a long `for loop` or `lapply` that I want to know the ongoing progress of. Something like the following is in the spirit of what I want but doesn't work: `lapply(1:n,function(i) { print(i); MAIN COMPUTATIONS })` Ideally the above would print `i` at the beginning of each new iteration of the `lapply`. QUESTION: How do I get ongoing progress updates of how many iterations my `lapply` or `for loop` has done?

Original source