Lecture 11: Design patterns and their benefits: clarity on what is to be done, flexibility about how to do it, ease of adapting others' solutions. The split/apply/combine pattern: divide big structured data sets up into smaller, related parts; apply the same analysis to each part independently; combine the results of the analyses. Trivial example: row and column means. Further examples. Iteration as a verbose, painful and clumsy implementation of split/apply/combine. Tools for...