Renaming levels of a factor in a dataframe

From: tyler_rinker at hotmail.com 
To: deelman at hotmail.com; r-help at r-project.org 
Subject: RE: [R] Renaming levels of a factor in a dataframe 
Date: Sun, 14 Aug 2011 13:18:12 -0400 

Here's an example of relevel used to relevel and combine groups.... 

InsectSprays2<-InsectSprays 
levels(InsectSprays2$spray) 
levels(InsectSprays2$spray)<-list(new1=c("A","C"),YEPS=c("B","D","E"),LASTLY="F") 
levels(InsectSprays2$spray) 
InsectSprays2 

So for you try... 
levels (Data1$Site) <- list(Fw =c( "AB"), Est = c("DE")) 

From: deelman at hotmail.com 
To: r-help at r-project.org 
Date: Sun, 14 Aug 2011 12:56:25 -0300 
Subject: [R] Renaming levels of a factor in a dataframe 



Dear Helplist: 



I am trying, unsuccessfully, to rename levels of a factor in a 

dataframe. The dataframe consists of two factor variables and one 
numeric variable as follows: 

Factor Site has 2 levels AB and DE, factor Fish has 30 levels, 15 

associated with each Site e.g. 1-1, 1-2,.....2-1, 2-2.... I am trying 
to rename the levels of factor Site from AB to Fw and DE to Est while 
keeping them as factors. The following 2 approaches do not work, each 
giving a NULL response and creating a character string. 

levels (Data1$Site <- c("Fw", "Est")) This simply gives an 

alternating list of Fw, Est, Fw, Est... not the desired 15 concurrent 
rows of Fw followed by 15 of Est. 

#levels (Data1$Site <- list(Fw = "AB", Est = "DE")) This gives the 

same result. I have tried other approaches to no avail. It seems a 
simple problem but has not been so. 

Any suggestions for solving this problem would be much appreciated. 



Regards, 

BJ