[R] Replacing a few variable values within a DataFrame...

[Jason Rupert]

Phil and all, 

Thank you for the responses.  That method worked great!


However, I did try to replace the a few of the "Variables" using the same method and received an error...

test_data2_df[test_data2_df$Location == 'HSV','Variables'] = "YardSize"

Is there something special I need to do in order to replace the string characters? 

Right now it appears "NA" is being used. 

Thank you again.

test_data2_df<-data.frame(Variables=c("SQR Footage","SQR Footage","SQR Footage","SQR Footage","SQR Footage","SQR Footage","SQR Footage","SQR Footage","SQR Footage","SQR Footage","SQR Footage","SQR Footage","SQR Footage","SQR Footage","SQR Footage"), 
HouseSize=c(10, 20, 30, 40, 50, 15, 25, 35, 45, 55, 18, 28, 38, 48, 58), Lot=c(1, 2, 3, 4, 5, 10, 20, 30, 40, 50, 11, 21, 31, 41, 51), 
Location = c("HSV", "ATH", "HSV", "ATH", "FLO", "HSV", "ATH", "HSV", "ATH",
"FLO", "HSV", "ATH", "HSV", "ATH", "FLO"))


--- On Mon, 3/23/09, Phil Spector <spector at stat.berkeley.edu> wrote:

> From: Phil Spector <spector at stat.berkeley.edu>
> Subject: Re: [R] Replacing a few variable values within a DataFrame...
> To: "Jason Rupert" <jasonkrupert at yahoo.com>
> Date: Monday, March 23, 2009, 12:48 PM
> Jason -
>     When you say that you want to change some values (if),
> but 
> leave others the same (else) I think that the else is very 
> important.  Here's how to use ifelse to do what you
> want:
> 
>     test_data2_df$HouseSize = ifelse(test_data2_df$Location
> == 'HSV',newvalue, test_data2_df$HouseSize)
> 
> Here's another way to selectively change values in a
> data frame:
> 
> test_data2_df[test_data2_df$Location ==
> 'HSV','HouseSize'] = newvalues
> 
> 
>                                         - Phil Spector
>  					 Statistical Computing Facility
>  					 Department of Statistics
>  					 UC Berkeley
>  					 spector at stat.berkeley.edu
> 
> 
> 
> On Mon, 23 Mar 2009, Jason Rupert wrote:
> 
> >
> > I would like to replace a few varaibles within a data
> frame.
> >
> > For example, in the dataframe below (contrived) I
> would like to replace the current housesize value only if
> the Location is HSV.   However, I would like to leave the
> other values intact.
> >
> >
> > I tried "ifelse", but I don't really
> need the else condition.
> >
> > test_data2_df<-data.frame(Variables=c("SQR
> Footage","SQR Footage","SQR
> Footage","SQR Footage","SQR
> Footage","SQR Footage","SQR
> Footage","SQR Footage","SQR
> Footage","SQR Footage","SQR
> Footage","SQR Footage","SQR
> Footage","SQR Footage","SQR
> Footage"),HouseSize=c(10, 20, 30, 40, 50, 15, 25, 35,
> 45, 55, 18, 28, 38, 48, 58), Lot=c(1, 2, 3, 4, 5, 10, 20,
> 30, 40, 50, 11, 21, 31, 41, 51), Location=c("HSV",
> "ATH", "HSV", "ATH",
> "FLO",
> >                                     "HSV",
> "ATH", "HSV", "ATH",
> "FLO",
> >                                     "HSV",
> "ATH", "HSV", "ATH",
> "FLO"))
> >
> > Moreover, I want to preserve the rest of the values
> within the data.  I thought some combination using the
> subset would get me there, but I ended up with a long and
> ungangly looking code.
> >
> > Thanks for any help that is offered.
> >
> > ______________________________________________
> > 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.
> >