Replace numbers in data frame column in R? [duplicate]

Question

Possible Duplicate:
Replace contents of factor column in R dataframe

I have the data.frame

df1<-data.frame("Sp1"=1:6,"Sp2"=7:12,"Sp3"=13:18) rownames(df1)=c("A","B","C","D","E","F")  df1   Sp1 Sp2 Sp3 A   1   7  13 B   2   8  14 C   3   9  15 D   4  10  16 E   5  11  17 F   6  12  18 

I want to replace every entry of the number 8 in the column df1$Sp2 with the number 800. I have tried:

test<-replace(df1$Sp2,df1[800,"Sp2"],5) 

Answer 1

e.g.:

df1$Sp2[df1$Sp2 == 8] <- 800