Editing Statistics and Statistical Programming (Winter 2017)/R lecture outline: Week 3
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** library(foreign) | ** library(foreign) | ||
* defining functions | * defining functions | ||
** | ** apply(), lapply(), sapply() | ||
** for looping | |||
* stuff related to distributions | * stuff related to distributions | ||
** rep() | ** rep() | ||
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** sample(); and sampling into data.frames | ** sample(); and sampling into data.frames | ||
Online supplement: | |||
* dates with POSIXct(). dates will almost always be given to you as characters, and you need to parse them | * other things that have come up | ||
* | ** dates with POSIXct(). dates will almost always be given to you as characters, and you need to parse them | ||
* | ** ordered() — really just a type of factor for ordinal data | ||
** merge() | |||
Skipped for now: | |||
** merge() | |||
** 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 | |||
