---
title: "A simple rmarkdown example"
author: "Wolfgang Viechtbauer"
date: "`r format(Sys.time(), '%d %B, %Y')`"
fig_caption: yes
bibliography: references.bib
---

# Introduction

This is an example of a R markdown document. With some basic formating codes you can make text *italic* and **bold**.

## Subheading

You can also easily make lists:

* item 1
* item 2
* item 3

Or numbered lists:

1. item 1
2. item 2
3. item 3

### Subsubheading

This is a "subsubheading".

## Equations

If you know some basic latex syntax, you can easily add equations to your document. Equations can appear as part of the regular text (e.g., if $x = 2$, then $x + 4 = 6$). Or you can have equations appear in their own line: $$\frac{1}{2} + \frac{3}{4} = \frac{5}{4}.$$ When you compile the document, the equations should be nicely rendered.

## Links

Links can be created by simply pasting the URL into the document: https://rmarkdown.rstudio.com/. Or, you can make a string of text become a link. For example, [R markdown](https://rmarkdown.rstudio.com/).

## Embedding R Code

Where it gets really cool is when you start embedding R code in your document. For example:

```{r}
set.seed(1234)
x <- runif(100, min=0, max=30)
y <- 10 + .5*x + .3*x^2 + rnorm(100, mean=0, sd=25)
res1 <- lm(y ~ x)
res2 <- lm(y ~ x + I(x^2))
summary(res1)
```

## Dynamically Generated Plots

Using regular R code, you can create graphs, which then get automatically embedded in the document.

```{r, fig.width=7, fig.height=5}
plot(x, y, pch=19, xlab="Time in R Course",
     ylab="Your R Skills", main="R Skills as a Function of Time in Course")
abline(res1, lty="dotted")
lines(predict(res2, newdata=data.frame(x=seq(0,30,1))))
```

You can also include the results from analyses in your text. For example, for the quadratic model, we find $R^2 =$ `r round(summary(res2)$r.squared, 2)`. I think we should send this article to Science or Nature!

## Tables

You can also create tables from model objects (the `pander` package is very useful for that).

```{r, echo=FALSE, message=FALSE, warning=FALSE}
if (!require(pander))
   install.packages("pander")
library(pander)
```

```{r, echo=FALSE, results='asis'}
pander(res2, caption="Results from Quadratic Model")
```

The `kable()` function from the `knitr` package can do something similar.

```{r, echo=FALSE, message=FALSE, warning=FALSE}
if (!require(knitr))
   install.packages("knitr")
library(knitr)
```

```{r, echo=FALSE, results='asis'}
kable(round(coef(summary(res2)), 3), caption="Results from Quadratic Model")
```

These are just some of the basics. I hope you can see the potential here!

## References

You can also include references. You need a bibliography file for this (see the `references.bib` file). For example, the first paper about the R language was written by @ihaka1996. Blah blah blah. We used R for the analyses [@r2020].

## More Info

To learn more about R Markdown, you should check out these websites:

* [rmarkdown](https://rmarkdown.rstudio.com/)
* [markdown](https://daringfireball.net/projects/markdown/)
* [pandoc](https://pandoc.org/)

These are some useful packages that can be useful when creating such documents.

* [pander package](https://rapporter.github.io/pander/)
* [xtable package](https://cran.r-project.org/package=xtable)
* [texreg package](https://cran.r-project.org/package=texreg)

# References
