knitr_examples.Rmd

---
title: "knitr::kable() and include_graphics() examples"
output:
  pdf_document: default
  html_notebook: 
    fig_caption: yes
---
```{r}
library(knitr)
```

Use `kable()` to produce pretty tables in pdf and Word output.  They are, however, less pretty in html output (including in-line output and Preview output).

```{r table}
head(trees)
```

```{r kabletable}
kable(head(trees))
```

Use `include_graphics()` to add already existing pictures.

Useful tips:

1. `fig.width` and `fig.length` don't affect images not made by R. You have to use the `out.width` chunk option which can accept quoted values like `"2in"` or `"50%"`.  Unfortunately, `out.width` doesn't affect in-line output or Preview output, only knit output.
2. To get figure captions, use chunk option `fig.cap=`. You must also enable figure captions in the output by adding `fig_captions: yes` to the YAML header under the output option (indented approriately, see above).  You can do this manually or by clicking the gear button next to the knit button and choosing *Output options..* and then checking the appropriate box.


```{r out.width="50%", fig.cap="kitteh!", fig.align='center'}
include_graphics("kitten.jpg")
```