Updated filepath to data.
Named figures.
Updated header syntax.
Removed parentheses from text references to functions for consistency with other lesson material.
Updated analyze function definintion.
Small aesthetic edits.
Changed sentence in first example of for loop. Added note about NA values. Also changed for loop to iterate through the elements instead of using indexing.
Added links to glossary and updated example with vowels.
Updated section that demonstrates loop variable can be reassigned. Also added link to lesson on data structures instead of discussing them here.
Updated challenge to write function that prints natural numbers. Remove superflous examples of seq, similar to proposed changes to novice Python lessons.
Updated challenge to write function that performs exponentionation.
Removed exercise on reversing a string. Doing this with a vector in R would require more than what we taught them at this point, and even more if they were to properly do it pre-allocating the new vector. Furthermore, this challenge section already contains two substantial exercises.
Removed section on mutable vs immutable data types because not overly relevant to programming in R. Also removed examples of extending vector since it no longer makes sense to introduce these here after removing the discussion above.
Updated challenge to sum the numbers in a vector, added an example, and combined it with the previous challenge section.
Updated section on Processing Multiple Files. Also fixed small error where the min and max were switched in the analyze function.
Aesthetic updates to section on advice for loops in R. Also updated file paths.
Added intro sentence to section on advice on loops.
Split in depth section on loops in R into its own file as a supplement to the main lessons. It is an important topic, but is a bit advanced for novices that just learned how to write a for loop.
Renamed supplementary lesson file so that it would be built by Makefile.
Added context to supplementary lesson on loops. Also have the demonstration of growing objects iterate over all 12 data files.