How to convert integer to factor? [duplicate]

Question

Say I have the following df

x<-c(1,3,2,4,1,3,2,4,1,3,2,4)
y<-c(rnorm(12))
df<-data.frame(x,y)

x is integer and I try to convert it to a factor using the suggestion from the R cookbook:

df[,'x']<-factor(df[,'x'])

But it still remains an integer. I have tried a solution found on the forum

df[,'x']<-lapply(df[,'x'], factor)

but it did not work either. Thanks.

Answer 1

It seems that your original solution works. Check the typeof() as well as the class():

x<-c(1,3,2,4,1,3,2,4,1,3,2,4)
y<-c(rnorm(12))
df<-data.frame(x,y)
typeof(df$x)
#"double"    
class(df$x)
#"numeric"
df[,'x']<-factor(df[,'x'])
typeof(df$x)
 #"integer"
class(df$x)
#"factor"