How to save a data frame in R

Question

According to the answer to this question, you can save a data frame "foo" in R with the save() function as follows:

save(foo,file="data.Rda")

Here is data frame "df":

> str(df)
'data.frame':   1254 obs. of  2 variables
$ text : chr  "RT @SchmittySays: I love this 1st grade #science teacher from #Duluth http://t.co/HWDYFnIyqV  #NSTA15 #AlbertEinstein #inspirat"| __truncated__ "RT @KVernonBHS: @smrtgrls would love Stellar Girls. Empowering female scientists rocks! #NSTA15 http://t.co/1ZU0yjVF67" "RT @leducmills: Leaving #SXSWedu to go straight to #NSTA15. There should be some sort of arbitrary conference-hopper social med"| __truncated__ "RT @KRScienceLady: Congrats to a wonderful colleague who  helped #ngss Bcome reality, Stephen Pruitt, Distinguished Service to "| __truncated__ ...
$ group: Factor w/ 2 levels "narst","nsta": 2 2 2 2 2 2 2 2 2 2 ...

It seems to save fine:

> save(df, file = "~/downloads/df.Rda")

But it turns out only the name of the object saved:

> df1 <- load("~/downloads/df.Rda")
> str(df1)
chr "df"

I tried the saveRDS() function suggested in another answer to the same question referenced above which worked fine, but I'd like to know why save() isn't working.

Answer 1

You might want to take a look at this question here: R data formats: RData, Rda, Rds etc.

When loading an .rda object, you are going to load all objects with their original names to the global environment. You can't assign objects to new names using load as you tried to do.

If you want to save objects that can be loaded with different names later, then you should use the .rds format (saveRDS and readRDS). If you want to save more than one object in a .rds file, the simplest solution is to put all of them on a list and save only the list. If after reading the .rds you want to put the objects of the list in the global environment, you can use list2env.