I'm adding a column (region) to a data frame (devUni8), and the (region) column will be populated by a numeric code that is a function of another column (state) in that data frame. See part of the script below. How can I rewrite this so that I could apply the conditions to any data frame without having to keep typing its name (in this case, "devUni8$"). I've heard the attach() function is to be avoided, and I'm not good at with, while, or if statements right now. I've tried some other things but keep getting "object not found" errors. Assistance appreciated. Thanks. #Create Region Variable ######### devUni8$region=0 #Assign Northeast States ######### devUni8$region[devUni8$state >= 11 & devUni8$state <= 23 | devUni8$state >51 & devUni8$state <= 55] = 1 #Assign Southeast States ######### devUni8$region[devUni8$state >= 56 & devUni8$state <= 64 ] = 2 -- View this message in context: http://r.789695.n4.nabble.com/rewrite-script-to-eliminate-constant-object-reference-tp4669393.html Sent from the R help mailing list archive at Nabble.com.
If you want an easy way to change the name of the data frame for assignment then you may want a macro. There is an article in the R journal ( http://cran.r-project.org/doc/Rnews/Rnews_2001-3.pdf) on creating macros and there are tools that help with creating macros in the gtools package. Though what you are trying to do may work a little better using `findInterval` or `merge`. On Wed, Jun 12, 2013 at 2:36 PM, bcrombie <bcrombie@utk.edu> wrote:> I'm adding a column (region) to a data frame (devUni8), and the (region) > column will be populated by a numeric code that is a function of another > column (state) in that data frame. See part of the script below. > > How can I rewrite this so that I could apply the conditions to any data > frame without having to keep typing its name (in this case, "devUni8$"). > I've heard the attach() function is to be avoided, and I'm not good at > with, > while, or if statements right now. I've tried some other things but keep > getting "object not found" errors. Assistance appreciated. Thanks. > > #Create Region Variable > ######### > devUni8$region=0 > > #Assign Northeast States > ######### > devUni8$region[devUni8$state >= 11 & devUni8$state <= 23 | devUni8$state >> 51 & devUni8$state <= 55] = 1 > > #Assign Southeast States > ######### > devUni8$region[devUni8$state >= 56 & devUni8$state <= 64 ] = 2 > > > > -- > View this message in context: > http://r.789695.n4.nabble.com/rewrite-script-to-eliminate-constant-object-reference-tp4669393.html > Sent from the R help mailing list archive at Nabble.com. > > ______________________________________________ > R-help@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. >-- Gregory (Greg) L. Snow Ph.D. 538280@gmail.com [[alternative HTML version deleted]]
Jim Holtman
2013-Jun-12 21:32 UTC
[R] rewrite script to eliminate constant object reference
Check out 'with' and 'within'. Sent from my Verizon Wireless 4G LTE Smartphone -------- Original message -------- From: bcrombie <bcrombie@utk.edu> Date: 06/12/2013 16:36 (GMT-05:00) To: r-help@r-project.org Subject: [R] rewrite script to eliminate constant object reference I'm adding a column (region) to a data frame (devUni8), and the (region) column will be populated by a numeric code that is a function of another column (state) in that data frame. See part of the script below. How can I rewrite this so that I could apply the conditions to any data frame without having to keep typing its name (in this case, "devUni8$"). I've heard the attach() function is to be avoided, and I'm not good at with, while, or if statements right now. I've tried some other things but keep getting "object not found" errors. Assistance appreciated. Thanks. #Create Region Variable ######### devUni8$region=0 #Assign Northeast States ######### devUni8$region[devUni8$state >= 11 & devUni8$state <= 23 | devUni8$state >51 & devUni8$state <= 55] = 1 #Assign Southeast States ######### devUni8$region[devUni8$state >= 56 & devUni8$state <= 64 ] = 2 -- View this message in context: http://r.789695.n4.nabble.com/rewrite-script-to-eliminate-constant-object-reference-tp4669393.html Sent from the R help mailing list archive at Nabble.com. ______________________________________________ R-help@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. [[alternative HTML version deleted]]
Hi,
Here are some examples using the mtcars dataset that you can modify to work
with your data.
## Here is my first try using within.
## Somehow the elements of region that
## should be zero are converted to NA
mtcars <- within(mtcars, {
region <- 0
region[gear==4&carb==4] <- 1
region[gear==3&carb==1] <- 2
})
## Here is a second try with an ugly
## hack to fix the NA problem
mtcars <- within(mtcars, {
region <- NA
region[gear==4&carb==4] <- 1
region[gear==3&carb==1] <- 2
region[is.na(region)] <- 0
})
## Here is an alternative using with
## instead of within
mtcars$region <- 0
mtcars$region[with(mtcars, gear==4&carb==4)] <- 1
mtcars$region[with(mtcars, gear==3&carb==1)] <- 2
Best,
Ista
On Wed, Jun 12, 2013 at 4:36 PM, bcrombie <bcrombie@utk.edu> wrote:
> I'm adding a column (region) to a data frame (devUni8), and the
(region)
> column will be populated by a numeric code that is a function of another
> column (state) in that data frame. See part of the script below.
>
> How can I rewrite this so that I could apply the conditions to any data
> frame without having to keep typing its name (in this case,
"devUni8$").
> I've heard the attach() function is to be avoided, and I'm not good
at
> with,
> while, or if statements right now. I've tried some other things but
keep
> getting "object not found" errors. Assistance appreciated.
Thanks.
>
> #Create Region Variable
> #########
> devUni8$region=0
>
> #Assign Northeast States
> #########
> devUni8$region[devUni8$state >= 11 & devUni8$state <= 23 |
devUni8$state >> 51 & devUni8$state <= 55] = 1
>
> #Assign Southeast States
> #########
> devUni8$region[devUni8$state >= 56 & devUni8$state <= 64 ] = 2
>
>
>
> --
> View this message in context:
>
http://r.789695.n4.nabble.com/rewrite-script-to-eliminate-constant-object-reference-tp4669393.html
> Sent from the R help mailing list archive at Nabble.com.
>
> ______________________________________________
> R-help@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.
>
[[alternative HTML version deleted]]