Create a waffle chart. — waffle

A waffle chart is a grid of squares (by default 10 x 10 = 100 cells) in which each category fills a number of cells proportional to its share of the whole. Each cell therefore reads as "one percent" (or one unit of the total), which makes part-to-whole comparisons far easier to read than a pie chart. The format is a staple of Pew Research Center, FiveThirtyEight, The Economist and the Washington Post, and was popularised in R by Bob Rudis's waffle package.

Cells are allocated with the largest-remainder method, so the cell counts always add up exactly to rows * cols. Unlike parliament_chart, which draws individual seats along a hemicycle, a waffle chart uses a rectangular grid to show proportions of a whole rather than absolute counts.

Usage

waffle_chart(
  data,
  category,
  value,
  rows = 10,
  cols = 10,
  total = NULL,
  colors = NULL,
  emptyCol = "#e5e5e5",
  cellPadding = 2,
  cellRadius = 2,
  direction = "row",
  legend = TRUE,
  legendFontSize = 12,
  hover = TRUE,
  animate = TRUE,
  animationDuration = 1200,
  title = NULL,
  titleFontSize = 16,
  font = "Verdana, Geneva, Tahoma, sans-serif",
  bgcol = "white",
  textCol = "black",
  width = NULL,
  height = NULL
)

Arguments

data: The data frame containing the variables to consider. It should contain one row per category.
category: The name of the categorical column used as labels.
value: The name of the numeric (non-negative) column holding each category's value.
rows: Number of rows in the grid. Defaults to 10.
cols: Number of columns in the grid. Defaults to 10. The total number of cells is rows * cols.
total: Optional. The value represented by the whole grid. Defaults to the sum of value. When larger than that sum, the remaining cells are left unfilled and drawn with emptyCol.
colors: Optional. A character vector of colors, one per category (recycled if shorter). Defaults to a Tableau-10 style palette.
emptyCol: Color of the unfilled cells. Defaults to "#e5e5e5".
cellPadding: Gap between cells in pixels. Defaults to 2.
cellRadius: Corner radius of each cell in pixels. Defaults to 2. Use 0 for sharp squares.
direction: Fill direction. "row" (default) fills row by row starting from the bottom-left corner (the Pew Research style), "col" fills column by column starting from the bottom-left corner.
legend: Whether to display a legend showing each category and its percentage. Defaults to TRUE.
legendFontSize: Font size of the legend text. Defaults to 12.
hover: Whether hovering a cell or a legend entry highlights that category and shows a label with its value and percentage. Defaults to TRUE.
animate: Whether the cells pop in sequentially when the chart loads. Defaults to TRUE.
animationDuration: Total duration of the load animation in milliseconds. Defaults to 1200.
title: Optional. Title of the chart.
titleFontSize: Font size of the chart title. Defaults to 16.
font: The font family used for all text. Defaults to "Verdana, Geneva, Tahoma, sans-serif".
bgcol: Background color of the SVG. Defaults to "white".
textCol: Color of the title and legend text. Defaults to "black".
width: Optional. The width of the SVG output.
height: Optional. The height of the SVG output.

Value

An SVG waffle chart.

Examples

# How respondents answered a survey question
survey <- data.frame(
  response = c("Strongly agree", "Agree", "Neutral",
               "Disagree", "Strongly disagree"),
  n = c(312, 405, 158, 87, 38)
)

waffle_chart(
  data     = survey,
  category = "response",
  value    = "n",
  colors   = c("#1a9641", "#a6d96a", "#bdbdbd", "#fdae61", "#d7191c"),
  title    = "Do you support the new policy?"
)


# Share of the world population by continent in 2007, filled by column
library(gapminder)

pop_2007 <- gapminder[gapminder$year == 2007, ]
pop_continent <- aggregate(pop ~ continent, data = pop_2007, FUN = sum)

waffle_chart(
  data      = pop_continent,
  category  = "continent",
  value     = "pop",
  direction = "col",
  rows      = 10,
  cols      = 20,
  title     = "World population by continent, 2007"
)