June 24, 2012
R Normal Distribution Functions

Density, distribution function, quantile function and random
generation for the normal distribution with mean equal to ‘mean’
and standard deviation equal to ‘sd’.

Use them this way:

dnorm(x, mean = 0, sd = 1, log = FALSE)
pnorm(q, mean = 0, sd = 1, lower.tail = TRUE, log.p = FALSE)
qnorm(p, mean = 0, sd = 1, lower.tail = TRUE, log.p = FALSE)
rnorm(n, mean = 0, sd = 1)

The math behind the code:

\[
f(x) = \frac{1}{(\sigma\sqrt{2 \pi})} e^{-(\frac{(x - \mu)^2}{2 \sigma^2})}
\]

Ten random draws from the normal distribution:

library(ggplot2)
qplot(1:10, rnorm(10), colour = runif(10))

plot of chunk unnamed-chunk-1

4:40pm  |   URL: http://tmblr.co/Z-5uyuO1zOB0
June 23, 2012
Test of markdownToHTML Output

\[f(x) = \frac{1}{(\sigma\sqrt{2 \pi})} e^{-(\frac{(x - \mu)^2}{2 \sigma^2})} \]

This is an R \(\sigma\) Markdown document. Markdown is a simple formatting syntax for authoring web pages (click the MD toolbar button for help on Markdown).

Another inline \( \sigma\sqrt{2 \pi} \) math equation.

here’s markdown superscript in action e2 and math inline equivalent \(e^2\).

This is an R \(\sigma\) Markdown document. Markdown is a simple formatting syntax for authoring web pages (click the MD toolbar button for help on Markdown).

When you click the Knit HTML button a web page will be generated that includes both content as well as the output of any embedded R code chunks within the document. You can embed an R code chunk like this:

summary(cars)

##      speed           dist    
##  Min.   : 4.0   Min.   :  2  
##  1st Qu.:12.0   1st Qu.: 26  
##  Median :15.0   Median : 36  
##  Mean   :15.4   Mean   : 43  
##  3rd Qu.:19.0   3rd Qu.: 56  
##  Max.   :25.0   Max.   :120

You can also embed plots, for example:

plot(cars)

plot of chunk unnamed-chunk-2

6:21pm  |   URL: http://tmblr.co/Z-5uyuN_GymC