[R] RGui: windows-record and command history

[P Ehlers]

Duncan Murdoch wrote:

> On 3/23/2006 10:34 AM, Peter Ehlers wrote:
> 
>> Duncan Murdoch wrote:
>>
>>> On 3/23/2006 7:35 AM, Thomas Steiner wrote:
>>>
>>>> a) How can I set the recording of all windows()-history forever to
>>>> "true"? I want something like windows(record = TRUE) but not just for
>>>> the window that opens then, but for all windows I will open ever.
>>>
>>>
>>>
>>> options(graphics.record=TRUE)
>>>
>>> will make that happen for the rest of the session.  To really make it 
>>> happen forever, you need to put this line in your Rprofile (see 
>>> ?Rprofile for where that comes from).
>>>
>>> Watch out though:  the graphics history is stored in your current 
>>> workspace in memory, and it can get big.  You might find you're 
>>> running out of memory if you store everything, and you'll find your 
>>> .RData files quite large if you save your workspace.
>>>
>>> On my todo list (but not for 2.3.0) is the possibility of setting a 
>>> default history length, perhaps defaulting to saving the last 2 or 3 
>>> pages.
>>
>> [snip]
>>
>> Duncan,
>>
>> This may be asking too much, but would it be possible to consider
>> implementing selective graph removal from the graph history?
>> I use graph.record=TRUE frequently for comparing graphs, but often
>> find that I'd like to kill one of the graphs while keeping others
>> in memory.
> 
> 
> That's probably not too hard to do in R code.  You just need to look at 
> the source in src/library/grDevices/R/windows/windows.R for the 
> print.SavedPlots method, and maybe the C level code in 
> src/library/grDevices/src/devWindows.c for a bit more help on the 
> interpretation of the .SavedPlots object, and then it should be fairly 
> straightforward to write a function that deletes an entry in the 
> history.  (It's a list with 5 components, the first 4 of which describe 
> the current state and what the user is looking at, and the last of which 
> is a list containing the actual recorded plots.)
> 
> Duncan Murdoch

Thanks, Duncan. I'll have a look at it.
Peter