Skip to contents

Warp your Facets with facetwarp

Introduction

facetwarp is an extension of ggplot2, specifically aimed at assisting in arranging faceted plots.

Typically facet_wrap positions your facets alphabetically, but with facet_warp you might:

  • layout facets as their categories appear on a map 🗺
  • arrange facets as if they themselves are points in a 2D scatter plot ⠞

Table of contents

  1. How it Works
  2. Installation
  3. Usage Examples
  4. Comparison to geofacet
  5. How to Contribute
  6. See Also

How it Works

facetwarp uses a solution to the Linear Assignment Problem developed by Jonker & Volgenant to take facets which can be expressed some 2D space, and snap them to a regular grid.

Installation 

devtools::install_github("mattdzugan/facetwarp")

Usage Examples

Hello facet_warp 🪄

Try it out! (note the warp not wrap after the facet) ✨

library(ggplot2)
library(facetwarp)
ggplot(iris)+
    geom_point(aes(x=Petal.Width, y=Petal.Length))+
    facet_warp(vars(Species), macro_x='Sepal.Width', macro_y='Sepal.Length', nrow = 3, ncol = 3)

facet_warp has re-positioned the facets! In fact, they are arranged to mimic the values of the Species’ respective Speal.Width and Speal.Length:

  • virginica at the top due to its high median_Sepal.Length
  • versicolor at the left due to its low median_Sepal.Width
  • setosa at the lower-right due to its low median_Sepal.Length and high median_Sepal.Width

A more interesting example: 

library(dplyr)
library(ggplot2)
library(facetwarp)


elections <- read.csv(file='https://gist.githubusercontent.com/mattdzugan/bf5bc48fad1850af59ac83a411f8c0d6/raw/8da67b51df907508f7c859fe29fc4637397513d8/County_Election_Data.csv')

ggplot(elections %>% filter(state_po == 'FL'))+
  labs(title='Florida Election Results by County', 
       y='proportion of votes')+
  theme_minimal()+
  theme(legend.position = 'None',
        panel.spacing = unit(1.2, "lines"), 
        axis.title = element_text(size = 18), 
        plot.title = element_text(size = 36), 
        axis.text = element_text(size = 8))+
  geom_rect(aes(xmin=year-4, xmax=year, ymin=(1-candidate_votes/total_votes), ymax=candidate_votes/total_votes, fill=party, alpha=candidate_votes/total_votes>.5))+
  geom_step(aes(x=year, y=candidate_votes/total_votes, color=party), direction='vh', linewidth=0.8)+
  scale_alpha_manual(values=c(0,0.3))+
  scale_color_manual(values=c('#5768ac','#e24a41'))+
  scale_fill_manual(values=c('#5768ac','#e24a41'))+
  scale_x_continuous(limits=c(2000,2020), breaks = seq(2000,2020,4))+
  facet_warp(vars(county_name),
             macro_x = 'lon',
             macro_y = 'lat',
             ncol = 12, nrow = 15)

Note the familiar shape of the state of Florida, since we used lat and lon as our macro variables.

Isn’t this the same as geofacet?

The idea of facetwarp is similar to that of geofacet, providing a few additional benefits:

  • The grid-arrangement is computed automatically given numerical data (such as lat and lon) - which unlocks the potential to create beautiful arrangements on ANY SET OF DATA
  • Since the arrangements are computed automatically, they are not limited to geospatial arrangements, but can use any numerical dimensions.

How to Contribute

This repo is just a brand new baby, so please open an issue, or reach out on twitter… i mean.. x.

See Also