Data replacement

Lisa wrote:

I have a dataset that looks like this: 

data

         id    code1    code2 
1         1        1        4 
2         1        2        3 
3         2        4        4 
..

I want to change some numbers in the columns of ?code1? and ?code2? based
on ?indx? as below

indx

[[1]]
        code 
1          1 
2          3 
3          4 
For example,  for the first ten records (rows) of my dataset, I want to
change 2 to 3, 3 to 4, 4 to 6, and 5 to 8 in both ?code1? and ?code2?,
while for the last ten records, I want to change 3 to 4 and 4 to 6.

You might check for "recode", for example in package car, or for
"transform". You could also do it the quick and dirty way, good to learn
indexing. Be careful if you have NA in your data, or data out of the
recode range.

Dieter


data = data.frame(code1=sample(1:5,10,TRUE),code2=sample(1:5,10,TRUE))
data =
rbind(data,data.frame(code1=sample(1:4,10,TRUE),code2=sample(1:4,10,TRUE)))

# The recode table as  in your example
#indx = list(data.frame(code=c(1,3,4,6,8)),data.frame(code=c(1,2,4,6)))

#easier to read
recode1 = c(1,3,4,6,8)
recode2 = c(1,2,4,6)

data$code1T[1:10] = recode1[data$code1[1:10]]
data$code2T[1:10] = recode1[data$code2[1:10]]

data$code1T[11:20] = recode2[data$code1[11:20]]
data$code2T[11:20] = recode2[data$code2[11:20]]