Editing Statistics and Statistical Programming (Winter 2017)/R lecture outline: Week 3

== Review of material from class ==

* loading data:
** load() versus read.csv()
** when things don't coopreate...
** library(foreign) 
* defining functions
** syntax for defining functions: show the my.mean function
** calling functions (your own or others) with apply(), lapply(), sapply()
* stuff related to distributions
** rep()
** seq()
** sample(); and sampling into data.frames

== Online only ==

* dates with POSIXct(). dates will almost always be given to you as characters, and you need to parse them
* tapply(), and putting things back into data.frames
* merge()


== Skipped for now == 

* ordered() — really just a type of factor for ordinal data

** distribution functions: lets focus on *unif(): the key is on page 222 of Verzani
*** The “d” functions return the p.d.f. of the distribution
**** dunif(x=1, min=0, max=3) # 1/3 of the area is the to the left 1
*** The “p” functions return the c.d.f. of the distribution.
**** dunif(q=2, min=0, max=3) #1/(b-a) is 2/3
*** The “q” functions return the quantiles.
**** qunif(p=0.5, min=0, max=3) # half way between 0 and 3
*** The “r” functions return random samples from a distribution.
**** runif(n=1, min=0, max=3) # a random value in [0,3]
* running quick simulations
** lets look at the relationship between mean and standard deviation on a 1 through 10 likert scale