R · Medium

Lesson 1 · On the house

vapply and mapply

Type-safe apply, SIMPLIFY, mapply recycling.

Lesson 2

Function formals and ...

formals, missing, ..., match.call sketch.

Lesson 3

Environments and <<-

environment(), parent.env, <<- vs <-, assign/get.

Lesson 4

Ordered factors and relevel

ordered(), relevel, droplevels, interaction.

Lesson 5

Dates with Date

as.Date, format, seq.Date, difftime, Sys.Date.

Lesson 6

Regex grep and gsub

grepl, grep, sub/gsub, fixed=, regmatches.

Lesson 7

S3 classes intro

structure/class, UseMethod, NextMethod, unclass.

Lesson 8

tryCatch and stopifnot

Handlers, finally, stop/warning/message, stopifnot.

Lesson 9

lm and formula

y ~ x, lm, coef/summary/predict, model.frame.

Lesson 10

Medium capstone

CSV → dates/factors → regex → vapply → lm → report.