Question

Suppose I have an .rda file created using save(). Example:

save(mydata1, file = "anrdatafile.rda")

where, mydata1 is a data frame.

I want to write code in R which: (1) loads the ‘anrdatafile.rda’ file; (2) finds the name of the data frame in that file (3) combines the found data frame with another data frame say mydata2.

How do I achieve step 2? Once I have the name of the data frame in step 2, I can do

combineddata = rbind(mydata1, mydata2)

But I don’t know how to get that the name of the dataframe in the .rda file is mydata1 as a part of a code.

I tried

nameofthedataframe = load('anrdatafile.rda')

This assigns the string “mydata1” to the variable “nameofthedataframe”, but then how do I get the data in the data frame mydata1?

To clarify, I know I can use the same data frame name that was to used to save the data. However, suppose I forget what the variable was. Or, more importantly, I would have to hard code the variable name in my code. I was wondering whether the program could figure out the name of the data frame during the run time once I gave it the file name.

Thanks. If it is not clear, please let me know. I will try to clarify.

Answer 1

If you have the name of an object, but you want the actual value, then use the get function. So you can do something like:

combineddata <- rbind( get(nameofthedataframe), mydata2 )