arun
2013-Sep-25 12:47 UTC
[R] Creating a new column to a data frame using a formula from another variable
Hi, Change: aa$z<-? eval(parse(text=bb)) ?aa #? x y? z #1 2 3? 3 #2 4 5? 7 #3 6 7 11 A.K. I want to create a new column to a data frame using a formula from another variable: Example: I have a data set "aa" is; x ? ?y 2 ? ?3 4 ? ?5 6 ? ?7 My R code is;>bb <- "x+y-2" >attach(aa) >aa$z<- bb >detach(aa)the result is; x ?y ?z 2 ?3 ?x+y-2 4 ?5 ?x+y-2 6 ?7 ?x+y-2 but I want like; x ?y ?z 2 ?3 ?3 4 ?5 ?7 6 ?7 ?11 Could you please help me..
arun
2013-Sep-25 12:52 UTC
[R] Creating a new column to a data frame using a formula from another variable
Also, Instead of ?attach, you could try ?with or ?within aa$z<- with(aa,eval(parse(text=bb))) aa$z #[1]? 3? 7 11 aa<- within(aa,z<- eval(parse(text=bb))) aa #? x y? z #1 2 3? 3 #2 4 5? 7 #3 6 7 11 A.K. ----- Original Message ----- From: arun <smartpink111 at yahoo.com> To: R help <r-help at r-project.org> Cc: Sent: Wednesday, September 25, 2013 8:47 AM Subject: Re: Re: Creating a new column to a data frame using a formula from another variable Hi, Change: aa$z<-? eval(parse(text=bb)) ?aa #? x y? z #1 2 3? 3 #2 4 5? 7 #3 6 7 11 A.K. I want to create a new column to a data frame using a formula from another variable: Example: I have a data set "aa" is; x ? ?y 2 ? ?3 4 ? ?5 6 ? ?7 My R code is;>bb <- "x+y-2" >attach(aa) >aa$z<- bb >detach(aa)the result is; x ?y ?z 2 ?3 ?x+y-2 4 ?5 ?x+y-2 6 ?7 ?x+y-2 but I want like; x ?y ?z 2 ?3 ?3 4 ?5 ?7 6 ?7 ?11 Could you please help me..