# Lecture 2 APPM2720 spring 2016

This lecture is an introduction to R and some
stats nuggets and experience in programming tossed in along the way.

The way to participate in this lecture is to

open R studio (just R will be OK too.)

load an R file in to your editting window

cut, paste R commands from your editting window into the R command window to run the code.

add more code and comments as you work through the
lecture and answer the questions.

when you are done ( or periodically) save your file in R studio.

The R scripts in this lecture cover

Basic housekeeping of your R workspace **RBasics.R**

Arithemtic and naming data sets (objects) **RMath.R**

Subsetting and extracting pieces of a data set **RSubsetting.R** (This will be assigned to work through outside of class.)

# R survival

R is case senitive

lines starting with # are comments

**help** help(plot) or ?plot gives you help documentation on a function or data set

When you quit R your workspace you will be asked to save your workspace. To recover past commands typed in see the history function. To save the workspace in your session use **save.image()** in the command window.

## The magnicifient seven

Basic functions to survive in R:

`ls`

lists the data sets in your workspace ls()

`rm`

removes a data set from your workspace rm(classGrades)

`<-`

assigns values to a data set a <- 3.5

`seq or :`

creates a sequence of equally spaced values. 1:4 or seq( 0,1,length.out=10)

`[ ]`

lets you select subsets of a data set or particular values. a[1:5] or b[1,2] or b[,3]

`c`

combines values or data sets a<- c( 3.5, 4.8)

`library`

loads an additional library to use in your R session library(dataWorkshop)

# Creating reports for homework assignments and projects

the notebook button (top line in the editting window a spiral notebook icon) in Rstudio will let you convert your R code into a spiffy report.

You can convert your R code into the markdown format to add text and still be able to "run" your code and get a good looking report. To get started create a blank R Markdown file using the green +
button, follow the hints and then fill it in!