[R] Why is rm(list=ls()) bad practice?

[Duncan Murdoch]

On 21/01/2021 5:20 p.m., J C Nash wrote:
> In a separate thread Jeff Newmiller wrote:
>> rm(list=ls()) is a bad practice... especially when posting examples. It doesn't clean out everything and it removes objects created by the user.
> 
> This query is to ask
> 
> 1) Why is it bad practice to clear the workspace when presenting an example?
> I'm assuming here that people who will try R-help examples will not run them in the
> middle of something else, which I agree would be unfortunates. 

I think that's exactly the concern.  I doubt it would have happened in 
this instance, but in other cases, people might copy and paste a 
complete example before reading it.  It's safer to say:  "Run this code 
in a clean workspace:", rather than cleaning it out yourself.

Duncan Murdoch


However, one of the
> not very nice aspects of R is that it is VERY easy to have stuff hanging around (including
> overloaded functions and operators) that get you into trouble, and indeed make it harder
> to reproduce those important "minimal reproducible examples".  This includes the .RData
> contents. (For information, I can understand the attraction, but I seem to have been
> burned much more often than I've benefited from a pre-warmed oven.)
> 
> 2) Is there a good command that really does leave a blank workspace? For testing
> purposes, it would be useful to have an assured blank canvas.

Yes, start R with

   R --vanilla

Duncan Murdoch

> 
> This post is definitely not to start an argument, but to try to find ways to reduce
> the possibilities for unanticipated outcomes in examples.
> 
> Cheers, JN
> 
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