ggforce.Rmd

---
title: "ggplot2 extensions: ggforce"
---

### ggforce
<https://github.com/thomasp85/ggforce>

ggforce is aimed at providing missing functionality to ggplot2 through the extension system introduced with ggplot2 v2.0.0.

```{r, message=FALSE,warning=FALSE}
# Example from https://github.com/thomasp85/ggforce
library(ggplot2)
library(ggforce)

# We'll start by defining some dummy data
pie <- data.frame(
    state = c('eaten', 'eaten but said you didn\'t', 'cat took it', 
              'for tonight', 'will decompose slowly'),
    focus = c(0.2, 0, 0, 0, 0),
    start = c(0, 1, 2, 3, 4),
    end = c(1, 2, 3, 4, 2*pi),
    amount = c(4,3, 1, 1.5, 6),
    stringsAsFactors = FALSE
)

p <- ggplot() + theme_no_axes() + coord_fixed()

# For low level control you define the start and end angles yourself
p + geom_arc_bar(aes(x0 = 0, y0 = 0, r0 = 0, r = 1, start = start, end = end, 
                     fill = state),
                 data = pie)

# Here are some data describing some circles
circles <- data.frame(
    x0 = rep(1:3, 2),
    y0 =  rep(1:2, each=3),
    r = seq(0.1, 1, length.out = 6)
)
ggplot() + geom_circle(aes(x0=x0, y0=y0, r=r, fill=r), data=circles)
```