Combine (rbind) data frames and create column with name of original data frames

Question

I have several data frames that I want to combine by row. In the resulting single data frame, I want to create a new variable identifying which data set the observation came

Answer 1

I'm not sure if such a function already exists, but this seems to do the trick:

bindAndSource <-  function(df1, df2) { 
  df1$source <- as.character(match.call())[[2]]
  df2$source <- as.character(match.call())[[3]]
  rbind(df1, df2)
}

results:

bindAndSource(df1, df2)

1 1 2    df1
2 3 4    df1
3 5 6    df2
4 7 8    df2

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Caveat: This will not work in *aply-like calls