This module’s assignment was to read data from a file, alter or filter that data, then write the new data to new files.

The code I used is on my GitHub repository here:

https://github.com/jered0/lis4930-rpackage/blob/master/module8/studentsorting.r

I was generally familiar with the concepts involved in reading from files thanks to other coding languages, and the format of read.table is pretty intuitive, so I had no problems there. The file.chooser() function was easy to use, and being able to read the data in all at once without looping through lines one at a time was nice.

It did take me a bit to wrap my head around the ddply function, but running it a few times and tweaking the parameters cleared it up. Being able to fiddle with a data set and pick it apart like that definitely seems like it would come in handy.

I’ve used the grep command on Unix often, so using grepl() was straightforward – though I did have to look over the documentation to see how grep() and grepl() differ, and why grepl needed to be used with subset().