R1.6.2 winnt. file.choose() gives an error if the dialog is cancelled without choosing a file. This can be easily dealt with via try(), but I would have thought that a NULL or NA return would be the expected behavior. Cheers, Bert Gunter Biometrics Research RY 84-16 Merck & Company P.O. Box 2000 Rahway, NJ 07065-0900 Phone: (732) 594-7765 mailto: bert_gunter@merck.com "The business of the statistician is to catalyze the scientific learning process." -- George E.P. Box ------------------------------------------------------------------------------
file.choose (PR#2465)
3 messages · bert_gunter@merck.com, Duncan Murdoch, Brian Ripley
On Thu, 16 Jan 2003 14:52:24 +0100 (MET), you wrote:
R1.6.2 winnt. file.choose() gives an error if the dialog is cancelled without choosing a file. This can be easily dealt with via try(), but I would have thought that a NULL or NA return would be the expected behavior.
I'd be worried that a change like that would lead to bugs downstream. Routines that make use of file.choose results would now have to check for invalid input. On the other hand, file.choose() could be more flexible. For example, the other day someone suggested to me that "install library from local zip file" should be able to install multiple packages at once, and that makes sense, but it requires multiple selections to be enabled in the file selection menu. There are a lot of other options to standard Windows file dialogs, but I can't spot any that would really be appropriate here. Can anyone else? Duncan Murdoch
On Fri, 17 Jan 2003, Duncan Murdoch wrote:
On Thu, 16 Jan 2003 14:52:24 +0100 (MET), you wrote:
R1.6.2 winnt. file.choose() gives an error if the dialog is cancelled without choosing a file. This can be easily dealt with via try(), but I would have thought that a NULL or NA return would be the expected behavior.
I'd be worried that a change like that would lead to bugs downstream. Routines that make use of file.choose results would now have to check for invalid input.
I agre..
On the other hand, file.choose() could be more flexible. For example, the other day someone suggested to me that "install library from local zip file" should be able to install multiple packages at once, and that makes sense, but it requires multiple selections to be enabled in the file selection menu. There are a lot of other options to standard Windows file dialogs, but I can't spot any that would really be appropriate here. Can anyone else?
Unfortunately file.choose() is a cross-platform function documented to return just one file name. It's a legacy of the MacOS beginnings, and no one has ever told me what the `new' argument was intended to do. I think we might to start again with choose.files(), with an argument that allowed multiple choices, and hope it can really be implemented on all the GUI-based interfaces (on Unix file.choose is not even based on choosing from a text list).
Brian D. Ripley, ripley@stats.ox.ac.uk Professor of Applied Statistics, http://www.stats.ox.ac.uk/~ripley/ University of Oxford, Tel: +44 1865 272861 (self) 1 South Parks Road, +44 1865 272866 (PA) Oxford OX1 3TG, UK Fax: +44 1865 272595