Don't use `setwd()`

[hadley]

Don't use `setwd()`

[ajdamico]

in general i'm with you 100% :) ..and i'm open to removing them.. in aiming to make these scripts accessible to beginners, i thought not setting the working directory might trip them up unnecessarily.. the cost of making it easy for more advanced users seemed outweighed by providing exact filepaths to beginners.. here's an especially tricky example ..think i'm catering to too unsophisticated of a user? or that that those exact filepaths just belong in the comments? :/

[hadley]

I think the goal should be that the scripts run without modification for the majority of users - which would imply that setwd() belong in the comments. I think monetdb is probably a bit of an exception because it requires substantial set up outside of R.

[ajdamico]

for all the scripts that don't use RMonetDB i have moved setwd() to the comments and added more explanation for new users ..it'll also be in the next commit. thanx :)