---
title: Rmd Beamer Example
author: John Doe
date: July 9, 2018
---
# Example of Beamer Slides from R Markdown

## Outline

- Instructions
- An image
- Two R code chunks
- An equation typeset in LaTeX
- References

## How to Create Beamer Slides from an Rmd file

- put title information in yaml prologue (optional)
- open a `.term` file and run these commands
- rendered view in Rmd editor may not look right - view the pdf file to see slides

```
  $ R
  > library(rmarkdown)
  > render("filename.Rmd", beamer_presentation())
  > quit()
  $ open filename.pdf
```


## Image

![NASA Exoplanet Exploration Program](figure/exoplanet_exploration.jpg)

## LaTeX

Radius of planet: $$r_p=r_s{\times}{\sqrt{\frac{{\Delta}B}{B}}}$$

Radius of planet's orbit: $$r=\sqrt[3]{\frac{G{M_s}{P^2}}{4{{\pi}^2}}}$$

## R Code Chunk 1

Get Data

```{r fetch_data}
qry  <- paste0("table=exoplanets&select=",
    "pl_hostname,",
    "pl_letter,",
    "pl_discmethod,pl_publ_date")
site <- paste0("http://exoplanetarchive.ipac.caltech.edu",
    "/cgi-bin/nstedAPI/nph-nstedAPI")
url <- paste0(site, "?", qry)
exo <- read.csv(url, stringsAsFactors=F)
exo$pl_discmethod <- as.factor(exo$pl_discmethod)
head(exo,3)
```

## R Code Chunk 2

Yield for different methods of discovery.
Use log scale on vertical axis


```{r plot_discmethod_logscale, echo=F}
exot <- table(exo$pl_discmethod)
exoto <- exot[order(exot,decreasing = T)]

par(mar=c(12.5,3,3.5, 0.3), cex.main=1.5)
barplot(exoto,las=2,col=rainbow(20),
  main="Exoplanets Discovered vs. Method",
  log="y", ylim=c(1,3000))
```

## References

Beamer User Guide
\newline
http://tug.ctan.org/macros/latex/contrib/beamer/doc/beameruserguide.pdf

R Markdown Presentations with Beamer
\newline
https://rmarkdown.rstudio.com/beamer_presentation_format.html

R function to create beamer slides
\newline
https://www.rdocumentation.org/packages/rmarkdown/versions/1.9/topics/beamer_presentation

NASA Exoplanet Exploration Program
\newline
https://exoplanets.nasa.gov/alien-worlds/exoplanet-travel-bureau/

