---
title: "Basic R Data Structures"
output: html_notebook
---

## A brief history of S, Splus and R

* **S1 (qpe)** -- original version internal to Bell Labs
    + Fortran interface
    + Copy on modify (preserve original data).
    + Data stored on disk.

* **S2** (Becker, Chambers & Wilks, 1988; _Blue Book_).  
    + vector
    + matrix, array
    + function
    + plot

* **S3** (Chambers & Hastie, 1992; _White Book_)
    + list
    + data.frame
    + formula & lm
    + class() -- Informal (S3) classes
    + UseMethod -- Informal Generic Functions

* **Splus** is commercial version of **S**

* **R** open source version of **S**
    + Input from XLISP-STAT
    + Workspace, not disk storage.

* **S4** (Chambers, 1998; _Green Book_)
   + Formal Classes & Generic Function
   + Really first implemented in *R*
   
* **R6** (Chambers, 2016)
   + Reference classes (like c++, java, &c)
   
# The Vector

## Storage modes

## The `c()` function

## Vectorized operations

## Summary operators

## Numerical Indexes

### Assignment & Indexes

## Negative indexes

## Logical Indexes

## The `if` statement

### isTRUE()

### all and any

## The `ifelse` function


## Named vectors

## Character indexes

## Vector exercises

# Matrixes and Arrays

## Column major order

## indexes

## row and column sums, apply function

## sweep operator

## arrays

## aperm

# functions

## writing functions

## functions as arguments

## anonymous functions

## Local and global variables

## Variable Scope

## Search Lists

## Function exercises


# lists

## The two extraction operators

## Named lists (dictionaries)

## The `$` extractor

## The `for` loop

```{r}
state.x77

```