Converting a pdataframe into dataframe

a<- data.frame(name=c(rep("a",5), rep("b",5)), year=c(1989:1993, 1989:1993), var=c(1:10))
str(a)
b<- pdata.frame(a, index=c("name","year"))
str(b)

Now, I want to convert b into a data frame and have a structure
similar to a. How do I do that?

I assume that pdata.frame() is the function in package plm.
(You should say so.)

The solution depends a bit on just how similar your new data
frame should be to a.

If you don't mind the attributes attached to each variable in b,
then do just

   new.b <- as.data.frame(b)

which will invoke the as.data.frame.pdata.frame() function.

If you want to strip the attributes, then this should do:

   new.b <- lapply(b, function(x){attr(x, "index") <- NULL; x})

In either case, 'year' will still be a factor and you may
still wish to 'unfactor' it; see ?factor.

Peter Ehlers
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