I woke up to Axios’ “1 Big Thing” ridgeline chart showing the crazy that was the 2019 news cycle:

and, I decided to reproduce it in {ggplot2}.

Getting The Data

First, I had to find the data. The Axios chart is interactive, so I assumed the visualization was built on-load. It was, but the data was embedded in a javascript file vs loaded as JSON via an XHR request:

which was easy enough to turn into JSON anyone can use.

library(ggalt)
library(hrbrthemes) # hrbrmstr/hrbrthemes
library(tidyverse)

jsonlite::fromJSON("https://rud.is/dl/2019-axios-news.json") %>% 
  as_tibble() -> xdf

xdf
## # A tibble: 31 x 3
##    name                    avg data      
##    <chr>                 <dbl> <list>    
##  1 Gov't shutdown        20.5  <int [51]>
##  2 Mexico-U.S. border    22.8  <int [51]>
##  3 Green New Deal        11.3  <int [51]>
##  4 Blackface              9.61 <int [51]>
##  5 N. Korea-Hanoi Summit 11.2  <int [51]>
##  6 Boeing 737 Max         4.79 <int [51]>
##  7 Brexit                28.5  <int [51]>
##  8 Israel                42.1  <int [51]>
##  9 SpaceX                24.1  <int [51]>
## 10 Game of Thrones       16.8  <int [51]>
## # … with 21 more rows

This is pretty tidy already, but we’ll need to expand the data column and give each week an index:

unnest(xdf, data) %>% 
  group_by(name) %>% 
  mutate(idx = 1:n()) %>% 
  ungroup() %>% 
  mutate(name = fct_inorder(name)) -> xdf # making a factor foe strip/panel ordering 

xdf
## # A tibble: 1,581 x 4
##    name             avg  data   idx
##    <fct>          <dbl> <int> <int>
##  1 Gov't shutdown  20.5    69     1
##  2 Gov't shutdown  20.5   100     2
##  3 Gov't shutdown  20.5    96     3
##  4 Gov't shutdown  20.5   100     4
##  5 Gov't shutdown  20.5    19     5
##  6 Gov't shutdown  20.5     9     6
##  7 Gov't shutdown  20.5    17     7
##  8 Gov't shutdown  20.5     3     8
##  9 Gov't shutdown  20.5     2     9
## 10 Gov't shutdown  20.5     1    10
## # … with 1,571 more rows

We’ll take this opportunity to find the first week of each month (via rle()) so we can have decent axis labels:

# get index placement for each month axis label
sprintf("2019-%02s-1", 1:51) %>% 
  as.Date(format = "%Y-%W-%w") %>% 
  format("%b") %>% 
  rle() -> mons

mons
## Run Length Encoding
##   lengths: int [1:12] 4 4 4 5 4 4 5 4 5 4 ...
##   values : chr [1:12] "Jan" "Feb" "Mar" "Apr" "May" "Jun" "Jul" "Aug" "Sep" "Oct" ...

month_idx <- cumsum(mons$lengths)-3

month_idx
##  [1]  1  5  9 14 18 22 27 31 36 40 44 48

We’ve got all we need to make a {ggplot2} version of the chart. Here’s the plan:

• use geom_area() and map colour and fill to avg (like Axios did), using an medium alpha value so we can still see below the overlapped areas
• also use an xspline() stat with geom_area() so we get smooth lines vs pointy ones
• use geom_hline() vs an axis line so we can map a colour aesthetic to avg as well
• make a custom x-axis scale so we can place the labels we just made
• expand the y-axis upper limit to avoid cutting off any part of the geoms
• use the inferno viridis palette, but not the extremes of it
• make facets/panels on the name, positioning the labels on the left
• finally, tweak strip positioning so we get overlapped charts

ggplot(xdf, aes(idx, data)) +
  geom_area(alpha = 1/2, stat = "xspline", aes(fill = avg, colour = avg)) +
  geom_hline(
    data = distinct(xdf, name, avg),
    aes(yintercept = 0, colour = avg), size = 0.5
  ) +
  scale_x_continuous(
    expand = c(0,0.125), limits = c(1, 51),
    breaks = month_idx, labels = month.abb
  ) +
  scale_y_continuous(expand = c(0,0), limits = c(0, 105)) +
  scale_colour_viridis_c(option = "inferno", direction = -1, begin = 0.1, end = 0.9) +
  scale_fill_viridis_c(option = "inferno", direction = -1, begin = 0.1, end = 0.9) +
  facet_wrap(~name, ncol = 1, strip.position = "left", dir = "h") +
  labs(
    x = NULL, y = NULL, fill = NULL, colour = NULL,
    title = "1 big thing: The insane news cycles of 2019",
    subtitle = "Height is search interest in a given topic, indexed to 100.\nColor is average search interest between Dec. 30, 2018–Dec. 20, 2019",
    caption = "Source: Axios <https://www.axios.com/newsletters/axios-am-1d9cd913-6142-43b8-9186-4197e6da7669.html?chunk=0#story0>\nData: Google News Lab. Orig. Chart: Danielle Alberti/Axios"
  ) +
  theme_ipsum_es(grid="X", axis = "") +
  theme(strip.text.y = element_text(angle = 180, hjust = 1, vjust = 0)) +
  theme(panel.spacing.y = unit(-0.5, "lines")) +
  theme(axis.text.y = element_blank()) +
  theme(legend.position = "none")

To produce this finished product:

FIN

The chart could be tweaked a bit more to get even closer to the Axios finished product.

Intrepid readers can also try to use {plotly} to make an interactive version.

Somehow, I get the feeling 2020 will have an even more frenetic news cycle.