Filter out rows from one data.frame that are present in another data.frame

Question

Suppose I have a larger data.frame and a smaller one. If the smaller one is contained inside the larger one, how can I subtract the rows of the smaller data.frame, leaving a result with the difference:

Larger - Smaller

Example:

Small data.frame:

     ID       CSF1PO CSF1PO.1 D10S1248 D10S1248.1 D12S391 D12S391.1 203079_BA_M     10       11       14         16      -9        -9 203079_BA_F      8       12       14         17      -9        -9 203080_BA_M     10       12       13         13      -9        -9 

Big data.frame:

      ID      CSF1PO CSF1PO.1 D10S1248 D10S1248.1 D12S391 D12S391.1 203078_MG_M     -9       -9       15         15      18        20 203078_MG_F     -9       -9       14         15      17        19 203079_BA_M     10       11       14         16      -9        -9 203079_BA_F      8       12       14         17      -9        -9 203080_BA_M     10       12       13         13      -9        -9 203080_BA_F     10       11       14         16      -9        -9 203081_MG_M     10       12       14         16      -9        -9 203081_MG_F     11       12       15         16      -9        -9 203082_MG_M     11       11       13         15      -9        -9 203082_MG_F     11       11       13         14      -9        -9 

The small data.frame corresponds to the rows 3, 4 and 5 of the larger data.frame.

Answer 1

Try this:

BigDF[ !(BigDF$ID %in% SmallDF$ID), ] 

Answer 2

In dplyr:

library(dplyr)  setdiff(BigDF, SmallDF) 

More Info: Hadley's dply cheatsheet: https://www.rstudio.com/wp-content/uploads/2015/02/data-wrangling-cheatsheet.pdf

Concise Set Operations functions with examples http://rpackages.ianhowson.com/cran/dplyr/man/setops.html (But the entire Grammar of Data Manipulation is a great resource overall)

And although the below is not in direct answer to your question - it is frequently related for me (and has been very useful)

If you wish to capture the new changes that have occured between a new dataframe and a previous version of the same dataframe (inside the same records) you will want to make your code look as below:

setdiff(NewDF, OldDF)