```{r global_options, include=FALSE} library(knitr) opts_chunk$set(fig.align="center", fig.height=4, fig.width=4) ``` ## In-class worksheet 1 **Jan 21, 2020** Much of the work in this class will be done via R Markdown documents. R Markdown documents are documents that combine text, R code, and R output, including figures. They are a great way to produce self-contained and documented statistical analyses. In this first worksheet, you will learn how to do some basic markdown editing. After you have made a change to the document, press "Knit HTML" in R Studio and see what kind of a result you get. Edit only below this line. --------------------------------------------- ## 1. Basic Markdown editing Try out basic R Markdown features, as described [here.](http://rmarkdown.rstudio.com/authoring_basics.html) Write some text that is bold, and some that is in italics. Make a numbered list and a bulleted list. Make a nested list. Try the block-quote feature. This text is **bold.** This text is *in italics.* A numbered list: 1. Item 1 2. Item 2 3. Item 3 A bulleted list: - Item 1 - Item 2 - Item 3 A nested list: 1. Item 1 - Item 1.1. Note that 4 spaces are required for the nesting to work properly. - Item 1.2 2. Item 2 Block quote: > "If we knew what it was we were doing, it would not be called research, would it?" --- Albert Einstein ## 2. Embedding R code R code embedded in R chunks will be executed and the output will be shown. ```{r} x <- 5 y <- 7 z <- x * y z ``` Play around with some basic R code. E.g., take the built-in data set `cars`, which lists speed and stopping distance for cars from the 1920. Plot speed vs. distance, and/or perform a correlation analysis. Then write a few sentences describing what you see. Plot of speed vs. distance: ```{r} plot(cars$dist, cars$speed) ``` Correlation analysis: ```{r} cor.test(cars$dist, cars$speed) ``` There is a strong positive correlations. Cars with higher speed have longer stopping distances. ## 3. If this was easy If this was easy, use Google to find out how to type-set mathematical formulas inside of R markdown. Mathematical equations are described [here.](https://support.rstudio.com/hc/en-us/articles/200486328-Equations-in-R-Markdown) For example, the geometric series: $$ \sum_{k=0}^\infty r^k = \frac{1}{1-r} $$ (Note that this only works if you are online, because a math rendering engine is downloaded on the fly.)