[R] Re storing a UPDATES on a data.frame

[savanna3000]

Thank you Prof Brian, this really solved my problem and it was well explained
:)



Prof Brian Ripley wrote:
> 
> Well
> 
> - MASS is a package and not a library
> - it is not 'base' but 'contributed', and as library(help=MASS) says, 
> support software for a book.  It is on CRAN.
> - Packages with namespaces are read-only, so you have not changed the 
> data frame in MASS, and even for other packages you can only change the 
> copy in memory, not that on disc (all 'unless you know to subvert the 
> standard ways').
> 
> What you likely did was to create a new data frame 'whiteside' in your 
> user workspace and then save the workspace containing it.  In which case
> 
> rm(whiteside)
> save.image()
> 
> will fix it.  However, you should have got warnings about conflicts when 
> you started R, but perhaps you forgot to mention those.
> 
> Perhaps the following might be educative:
> 
>> library(MASS)
>> find("whiteside")
> [1] "package:MASS"
>> whiteside$temp <- 1
>> find("whiteside")
> [1] ".GlobalEnv"   "package:MASS"
> 
> This is really an internal version of
> 
> whiteside <- `$<-`(whiteside, temp, 1)
> 
> and that assigns in the current frame just like  any other assignment.
> 
> 
> On Fri, 15 Feb 2008, savanna3000 wrote:
> 
>>
>> Hello everyone,
>>
>>  Can anyone tell me how do I restore data in a data.frame provided by
>> base
>> R libraries (MASS) ?
>> I uninstalled R then installed it again and I still see the new changes I
>> made!!!???
>> (eg. whiteside$Temp=1 ==> 1 overwrote all the rows, I want the old values
>> :(
>> !!
>>
>>
>>  Please HELP!
>> --
>> View this message in context:
>> http://www.nabble.com/Restoring-a-UPDATES-on-a-data.frame-tp15512767p15512767.html
>> Sent from the R help mailing list archive at Nabble.com.
>>
>> ______________________________________________
>> R-help at r-project.org mailing list
>> https://stat.ethz.ch/mailman/listinfo/r-help
>> PLEASE do read the posting guide
>> http://www.R-project.org/posting-guide.html
>> and provide commented, minimal, self-contained, reproducible code.
>>
> 
> -- 
> Brian D. Ripley,                  ripley at 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
> 
> ______________________________________________
> R-help at r-project.org mailing list
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide
> http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.
> 
> 

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