In trinker/reports: An R Package to Assist in the Workflow of Writing Academic Articles and Other Reports

dt:10

# make this an external chunk that can be included in any file
options(width = 70)
opts_chunk$set(message = F, error = F, warning = F, comment = NA, fig.align = 'center', dpi = 100, tidy = F, cache = T, cache.path = '.cache/', fig.path = 'assets/fig/')

options(xtable.type = 'html')
knit_hooks$set(inline = function(x) {
  if(is.numeric(x)) {
    round(x, getOption('digits'))
  } else {
    paste(as.character(x), collapse = ', ')
  }
})
knit_hooks$set(plot = knitr:::hook_plot_html)

Important simulation functions

Distributions * rbeta, rbinom, rcauchy, rchisq, rexp, rf, rgamma, rgeom, rhyper, rlogis, rlnorm, rnbinom, rnorm, rpois, rt, runif, rweibull

Densities

• dbeta,dbinom, dcauchy, dchisq, dexp, df, dgamma, dgeom, dhyper, dlogis, dlnorm, dnbinom, dnorm, dpois, dt, dunif, dweibull

Sampling * sample(,replace=TRUE),sample(replace=FALSE)

--- dt:20

r_foo_ functions generate data

Normal

args(rnorm)
heights = rnorm(10,mean=188,sd=3)
heights

--- dt:30

r_foo_ functions generate data

Binomial

args(rbinom)
coinFlips = rbinom(10,size=10,prob=0.5)
coinFlips

---

Example distribution: Normal

Normal Distribution: $N(\mu,\sigma)$ * $X \sim N(0,1)$

xvals = seq(-10,10,length=100)
plot(xvals,dnorm(xvals,0,1),type="l",col="blue",lwd=3,ylab="density",xlab="X value")

---

d_foo_ functions calculate the density

Normal

args(dnorm)
x = seq(from=-5,to=5,length=10)
normalDensity = dnorm(x,mean=0,sd=1)
round(normalDensity,2)

---

Example distribution: Binomial

Binomial distribution: $Bin(n,p)$ * $X \sim Bin(10,0.5)$

xvals = 0:10
plot(xvals,dbinom(xvals,10,0.5),type="h",col="blue",lwd=3,ylab="probability",xlab="X value")

---

d_foo_ functions calculate the density

Binomial

args(dbinom)
x = seq(0,10,by=1)
binomialDensity = dbinom(x,size=10,prob=0.5)
round(binomialDensity,2)

---

Sample draws a random sample

args(sample)
heights = rnorm(10,mean=188,sd=3)
heights
sample(heights,size=10,replace=TRUE)

---

Sample draws a random sample

heights
sample(heights,size=10,replace=FALSE)

---

Sample can draw according to a set of probabilities

heights
probs = c(0.4,0.3,0.2,0.1,0,0,0,0,0,0)
sum(probs)
sample(heights,size=10,replace=TRUE,prob=probs)

---

Setting a seed

Setting a seed ensures reproducible results from random processes in R

set.seed(12345)
rnorm(5,mean=0,sd=1)

set.seed(12345)
rnorm(5,mean=0,sd=1)

---

For more information

More on distributions in R

http://cran.r-project.org/web/views/Distributions.html

Computing for Data Analysis

Simulation in R

---

<section class="video" id="video">
  <video id='player' controls style='width:200px;height:150px;'>
    <source src="assets/media/simulations.mp4" type="video/mp4" />
  </video>
</section>

--- &popcorn

trinker/reports documentation built on May 31, 2019, 9:51 p.m.