I have datasets called example1,example2,example3,example4 of which variable is SEX(1 or 2) in working library
and I've made datasets called exampleS1,exampleS2,exampleS3,exampleS4 restricted to SEX=1 by using MACRO in SAS
like this way.
%macro ms(var=);
data exampleS&var.;
set example&var.; IF SEX=1;
run;
%mend ms;%ms(var=1);%ms(var=2);%ms(var=3);%ms(var=4);
Now, I want to do this job in R
It's bit not easy to do this in R to me. How can I do it? (assuming example1,example2, example3,example4 are data.frames)
Thank you in advance.
Having variables with numeric index in the name is a very SAS thing to do, and not at all very R like. If you have related data.frames, in R, you keep them in a list. There are many ways to read in many files into a list (see here). So say you have a list of data.frames
examples <- list(
data.frame(id=1:3, SEX=c(1,2,1)),
data.frame(id=4:6, SEX=c(1,1,2)),
data.frame(id=7:9, SEX=c(2,2,1))
)
Then you can get all the SEX=1 values with
exampleS <- lapply(examples, subset, SEX==1)
and you access them with
exampleS[[1]]
exampleS[[2]]
exampleS[[3]]
You should program R the R-way, not the SAS-way, because this will lead to endless pain. SAS-macro-language and R don't mix imo, but this is how:
# create example df's
for (i in 1:4) {
assign(paste0("example", i), data.frame(sex = sample(0:1, 10, replace = T)))
}
example1; example2; example3; example4
# filter and store result in a list of df's
l <- list(example1 = example1, example2 = example2, example3 = example3, example4 = example4)
want <- lapply(l, function(x) subset(x, sex == 1))
want$example1; want$example2; want$example3; want$example4 # get list of data frames
# almost certainly what you should do
# in principle possible to this too, but advise against it
list2env(lapply(l, function(x) subset(x, sex == 1)), .GlobalEnv)
example1; example2; example3; example4
