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Category Archives: Charts & Graphs

>UPDATE: Since I put in a “pull request” requirement, I intended to put in a link to getting started with GitHub. Dr. Jenny Bryan’s @stat545 has a great [section on git](https://stat545-ubc.github.io/git00_index.html) that should hopefully make it a bit less painful.

### Why 52Vis?

In case folks are wondering why I’m doing this, it’s pretty simple. We need a society that has high data literacy and we need folks who are capable of making awesome, truthful data visualizations. The only way to do that is by working with data over, and over, and over, and over again.

Directed projects with some reward are one of the best Pavlovian ways to accomplish that :-)

### This week’s challenge

The Data is Plural folks have [done it again](http://tinyletter.com/data-is-plural/letters/data-is-plural-2016-04-06-edition) and there’s a neat and important data set in this week’s vis challenge.

From their newsletter:

>_Every January, at the behest of the U.S. Department of Housing and Urban Development, volunteers across the country attempt to count the homeless in their communities. The result: HUD’s “point in time” estimates, which are currently available for 2007–2015. The most recent estimates found 564,708 homeless people nationwide, with 75,323 of that count (more than 13%) living in New York City._

I decided to take a look at this data by seeing which states had the worst homeless problem per-capita (i.e. per 100K population). I’ve included the population data along with some ready-made wrangling of the HUD data.

But, before we do that…

### RULES UPDATE + Last week’s winner

I’ll be announcing the winner on Thursday since I:

– am horribly sick after being exposed to who knows what after rOpenSci last week in SFO :-)
– have been traveling like mad this week
– need to wrangle all the answers into the github repo and get @laneharrison (and his students) to validate my choice for winner (I have picked a winner)

Given how hard the wrangling has been, I’m going to need to request that folks both leave a blog comment and file a PR to [the github repo](https://github.com/52vis/2016-14) for this week. Please include the code you used as well as the vis (or a link to a working interactive vis)

### PRIZES UPDATE

Not only can I offer [Data-Driven Security](http://dds.ec/amzn), but Hadley Wickham has offered signed copies of his books as well, and I’ll keep in the Amazon gift card as a catch-all if you have more (NOTE: if any other authors want to offer up their tomes shoot me a note!).

### No place to roam

Be warned: this was a pretty depressing data set. I went in with the question of wanting to know which “states” had the worst problem and I assumed it’d be California or New York. I had no idea it would be what it was and the exercise shattered some assumptions.

NOTE: I’ve included U.S. population data for the necessary time period.

library(readxl)
library(purrr)
library(dplyr)
library(tidyr)
library(stringr)
library(ggplot2)
library(scales)
library(grid)
library(hrbrmisc)
 
# grab the HUD homeless data
 
URL <- "https://www.hudexchange.info/resources/documents/2007-2015-PIT-Counts-by-CoC.xlsx"
fil <- basename(URL)
if (!file.exists(fil)) download.file(URL, fil, mode="wb")
 
# turn the excel tabs into a long data.frame
yrs <- 2015:2007
names(yrs) <- 1:9
homeless <- map_df(names(yrs), function(i) {
  df <- suppressWarnings(read_excel(fil, as.numeric(i)))
  df[,3:ncol(df)] <- suppressWarnings(lapply(df[,3:ncol(df)], as.numeric))
  new_names <- tolower(make.names(colnames(df)))
  new_names <- str_replace_all(new_names, "\\.+", "_")
  df <- setNames(df, str_replace_all(new_names, "_[[:digit:]]+$", ""))
  bind_cols(df, data_frame(year=rep(yrs[i], nrow(df))))
})
 
# clean it up a bit
homeless <- mutate(homeless,
                   state=str_match(coc_number, "^([[:alpha:]]{2})")[,2],
                   coc_name=str_replace(coc_name, " CoC$", ""))
homeless <- select(homeless, year, state, everything())
homeless <- filter(homeless, !is.na(state))
 
# read in the us population data
uspop <- read.csv("uspop.csv", stringsAsFactors=FALSE)
uspop_long <- gather(uspop, year, population, -name, -iso_3166_2)
uspop_long$year <- sub("X", "", uspop_long$year)
 
# normalize the values
states <- count(homeless, year, state, wt=total_homeless)
states <- left_join(states, albersusa::usa_composite()@data[,3:4], by=c("state"="iso_3166_2"))
states <- ungroup(filter(states, !is.na(name)))
states$year <- as.character(states$year)
states <- mutate(left_join(states, uspop_long), homeless_per_100k=(n/population)*100000)
 
# we want to order from worst to best
group_by(states, name) %>%
  summarise(mean=mean(homeless_per_100k, na.rm=TRUE)) %>%
  arrange(desc(mean)) -> ordr
 
states$year <- factor(states$year, levels=as.character(2006:2016))
states$name <- factor(states$name, levels=ordr$name)
 
# plot
#+ fig.retina=2, fig.width=10, fig.height=15
gg <- ggplot(states, aes(x=year, y=homeless_per_100k))
gg <- gg + geom_segment(aes(xend=year, yend=0), size=0.33)
gg <- gg + geom_point(size=0.5)
gg <- gg + scale_x_discrete(expand=c(0,0),
                            breaks=seq(2007, 2015, length.out=5),
                            labels=c("2007", "", "2011", "", "2015"),
                            drop=FALSE)
gg <- gg + scale_y_continuous(expand=c(0,0), labels=comma, limits=c(0,1400))
gg <- gg + labs(x=NULL, y=NULL,
                title="US Department of Housing & Urban Development (HUD) Total (Estimated) Homeless Population",
                subtitle="Counts aggregated from HUD Communities of Care Regional Surveys (normalized per 100K population)",
                caption="Data from: https://www.hudexchange.info/resource/4832/2015-ahar-part-1-pit-estimates-of-homelessness/")
gg <- gg + facet_wrap(~name, scales="free", ncol=6)
gg <- gg + theme_hrbrmstr_an(grid="Y", axis="", strip_text_size=9)
gg <- gg + theme(axis.text.x=element_text(size=8))
gg <- gg + theme(axis.text.y=element_text(size=7))
gg <- gg + theme(panel.margin=unit(c(10, 10), "pt"))
gg <- gg + theme(panel.background=element_rect(color="#97cbdc44", fill="#97cbdc44"))
gg <- gg + theme(plot.margin=margin(10, 20, 10, 15))
gg

percapita

I used one of HUD’s alternate, official color palette colors for the panel backgrounds.

Remember, this is language/tool-agnostic & go in with a good question or two, augment as you feel you need to and show us your vis!

Week 2’s content closes 2016-04-12 23:59 EDT

Contest GitHub Repo:

>UPDATE: Deadline is now 2016-04-05 23:59 EDT; next vis challenge is 2016-04-06!

Per a suggestion, I’m going to try to find a neat data set (prbly one from @jsvine) to feature each week and toss up some sample code (99% of the time prbly in R) and offer up a vis challenge. Just reply in the comments with a link to a gist/repo/rpub/blog/etc (or post directly, though inserting code requires some markup that you can ping me abt) post containing the code & vis with a brief explanation. I’ll gather up everything into a new github organization I made for this context. You can also submit a PR right to [this week’s repo](https://github.com/52vis/2016-13).

Winners get a free digital copy of [Data-Driven Security](http://amzn.to/ddsec), and if you win more than once I’ll come up with other stuff to give away (either an Amazon gift card, a book or something Captain America related).

Submissions should include a story/angle/question you were trying to answer, any notes or “gotchas” that the code/comments doesn’t explain and a [beautiful] vis. You can use whatever language or tool (even Excel or _ugh_ Tableau), but you’ll have to describe what you did step-by-step for the GUI tools or record a video, since the main point about this contest is to help folks learn about asking questions, munging data and making visualizations. Excel & Tableau lock that knowledge in and Tableau even locks that data in.

### Droning on and on

Today’s data source comes from this week’s Data Is Plural newsletter and is all about drones. @jsvine linked to the [main FAA site](http://www.faa.gov/uas/law_enforcement/uas_sighting_reports/) for drone sightings and there’s enough ways to slice the data that it should make for some interesting story angles.

I will remove one of those angles with a simple bar chart of unmanned aircraft (UAS) sightings by week, using an FAA site color for the bars. I wanted to see if there were any overt visual patterns in the time of year or if the registration requirement at the end of 2015 caused any changes (I didn’t crunch the numbers to see if there were any actual patterns that could be found statistically, but that’s something y’all can do). I’m not curious as to what caused the “spike” in August/September 2015 and the report text may have that data.

I’ve put this week’s example code & data into the [52 vis repo](https://github.com/52vis/2016-13) for this week.

library(ggplot2)
library(ggalt)
library(ggthemes)
library(readxl)
library(dplyr)
library(hrbrmisc)
library(grid)
 
# get copies of the data locally
 
URL1 <- "http://www.faa.gov/uas/media/UAS_Sightings_report_21Aug-31Jan.xlsx"
URL2 <- "http://www.faa.gov/uas/media/UASEventsNov2014-Aug2015.xls"
 
fil1 <- basename(URL1)
fil2 <- basename(URL2)
 
if (!file.exists(fil1)) download.file(URL1, fil1)
if (!file.exists(fil2)) download.file(URL2, fil2)
 
# read it in
 
xl1 <- read_excel(fil1)
xl2 <- read_excel(fil2)
 
# munge it a bit so we can play with it by various calendrical options
 
drones <- setNames(bind_rows(xl2[,1:3],
                             xl1[,c(1,3,4)]), 
                   c("ts", "city", "state"))
drones <- mutate(drones, 
                 year=format(ts, "%Y"), 
                 year_mon=format(ts, "%Y%m"), 
                 ymd=as.Date(ts), 
                 yw=format(ts, "%Y%V"))
 
# let's see them by week
by_week <- mutate(count(drones, yw), wk=as.Date(sprintf("%s1", yw), "%Y%U%u")-7)
 
# this looks like bad data but I didn't investigate it too much
by_week <- arrange(filter(by_week, wk>=as.Date("2014-11-10")), wk)
 
# plot
 
gg <- ggplot(by_week, aes(wk, n))
gg <- gg + geom_bar(stat="identity", fill="#937206")
gg <- gg + annotate("text", by_week$wk[1], 49, label="# reports", 
                    hjust=0, vjust=1, family="Cabin-Italic", size=3)
gg <- gg + scale_x_date(expand=c(0,0))
gg <- gg + scale_y_continuous(expand=c(0,0))
gg <- gg + labs(y=NULL,
                title="Weekly U.S. UAS (drone) sightings",
                subtitle="As reported to the Federal Aviation Administration",
                caption="Data from: http://www.faa.gov/uas/law_enforcement/uas_sighting_reports/")
gg <- gg + theme_hrbrmstr(grid="Y", axis="X")
gg <- gg + theme(axis.title.x=element_text(margin=margin(t=-6)))
gg

RStudioScreenSnapz024

### Fin

I’ll still keep up a weekly vis from the Data Is Plural weekly collection even if this whole contest thing doesn’t take root with folks. You can never have too many examples for budding data folks to review.

Folks who’ve been tracking this blog on R-bloggers probably remember [this post](https://rud.is/b/2014/11/16/moving-the-earth-well-alaska-hawaii-with-r/) where I showed how to create a composite U.S. map with an Albers projection (which is commonly referred to as AlbersUSA these days thanks to D3).

I’m not sure why I didn’t think of this earlier, but you don’t _need_ to do those geographical machinations every time you want a prettier & more inclusive map (Alaska & Hawaii have been states for a while, so perhaps we should make more of an effort to include them in both data sets and maps). After doing the map transformations, the composite shape can be saved out to a shapefile, preferably GeoJSON since (a) you can use `geojsonio::geojson_write()` to save it and (b) it’s a single file vs a ZIP/directory.

I did just that and saved both state and country maps out with FIPS codes and other useful data slot bits and created a small data package : [`albersusa`](https://github.com/hrbrmstr/albersusa) : with some helper functions. It’s not in CRAN yet so you need to `devtools::install_github(“hrbrmstr/albersusa”)` to use it. The github repo has some basic examples, heres a slightly more complex one.

### Mapping Obesity

I grabbed an [obesity data set](http://www.cdc.gov/diabetes/data/county.html) from the CDC and put together a compact example for how to make a composite U.S. county choropleth to show obesity rates per county (for 2012, which is the most recent data). I read in the Excel file, pull out the county FIPS code and 2012 obesity rate, then build the choropleth. It’s not a whole lot of code, but that’s one main reason for the package!

library(readxl)
library(rgeos)
library(maptools)
library(ggplot2)   # devtools::install_github("hadley/ggplot2") only if you want subtitles/captions
library(ggalt)
library(ggthemes)
library(albersusa) # devtools::install_github("hrbrmstr/albersusa")
library(viridis)
library(scales)
 
# get the data and be nice to the server and keep a copy of the data for offline use
 
URL <- "http://www.cdc.gov/diabetes/atlas/countydata/OBPREV/OB_PREV_ALL_STATES.xlsx"
fil <- basename(URL)
if (!file.exists(fil)) download.file(URL, fil)
 
# it's not a horrible Excel file, but we do need to hunt for the data
# and clean it up a bit. we just need FIPS & 2012 percent info
 
wrkbk <- read_excel(fil)
obesity_2012 <- setNames(wrkbk[-1, c(2, 61)], c("fips", "pct"))
obesity_2012$pct <- as.numeric(obesity_2012$pct) / 100
 
# I may make a version of this that returns a fortified data.frame but
# for now, we just need to read the built-in saved shapefile and turn it
# into something ggplot2 can handle
 
cmap <- fortify(counties_composite(), region="fips")
 
# and this is all it takes to make the map below
 
gg <- ggplot()
gg <- gg + geom_map(data=cmap, map=cmap,
                    aes(x=long, y=lat, map_id=id),
                    color="#2b2b2b", size=0.05, fill=NA)
gg <- gg + geom_map(data=obesity_2012, map=cmap,
                    aes(fill=pct, map_id=fips),
                    color="#2b2b2b", size=0.05)
gg <- gg + scale_fill_viridis(name="Obesity", labels=percent)
gg <- gg + coord_proj(us_laea_proj)
gg <- gg + labs(title="U.S. Obesity Rate by County (2012)",
                subtitle="Content source: Centers for Disease Control and Prevention",
           caption="Data from http://www.cdc.gov/diabetes/atlas/countydata/County_ListofIndicators.html")
gg <- gg + theme_map(base_family="Arial Narrow")
gg <- gg + theme(legend.position=c(0.8, 0.25))
gg <- gg + theme(plot.title=element_text(face="bold", size=14, margin=margin(b=6)))
gg <- gg + theme(plot.subtitle=element_text(size=10, margin=margin(b=-14)))
gg

Fullscreen_3_29_16__9_06_AM

### Fin

Note that some cartographers think of this particular map view the way I look at a pie chart, but it’s a compact & convenient way to keep the states/counties together and will make it easier to include Alaska & Hawaii in your cartographic visualizations.

The composite GeoJSON files are in:

– `system.file(“extdata/composite_us_states.geojson.gz”, package=”albersusa”)`
– `system.file(“extdata/composite_us_counties.geojson.gz”, package=”albersusa”)`

if you want to use them in another program/context.

Drop an issue [on github](https://github.com/hrbrmstr/albersusa) if you want any more default fields in the data slot and if you “need” territories (I’d rather have a PR for the latter tho :-).

As I said, I’m kinda obsessed with the “nuclear” data set. So much so that I made a D3 version that’s similar to the R version I made the other day. I tried not to code much today (too much Easter fun going on), so I left off the size & color legends, but it drops the bombs and fills the radiation meters bars as each year progresses.

Working in raw D3 reminds me how nice it is to work in R. Much cruft is abstracted away and the “API” in R (at least list ops and ggplot2) seem more consistent or at least less verbose.

One big annoyance (besides tweaking projection settings) is that I had to set:

script-src 'self' 'unsafe-eval';

on the [content security policy](http://content-security-policy.com/) since D3 uses “eval” a bit.

It’s embedded below and you can bust the frame via [this link](/projects/nucleard3/index.html). I made no effort to have it fit on tiny screens (it just requires fidgeting with the heights/widths of things), but it’s pretty complete code (including browser/touch icons, content security policy & open graph tags) and it’s annotated to help R folks map between ggplot2 and D3. If you build anything on it, drop a note in the comments.



> UPDATE: For folks interested in what this might look like in D3, [take a gander](https://rud.is/b/2016/03/27/nuclear-animations-in-d3/)

@jsvine (Data Editor at BuzzFeed) cleaned up and posted a [data sets of historical nuclear explosions](https://github.com/data-is-plural/nuclear-explosions) earlier this week. I used it to show a few plotting examples in class, but it’s also a really fun data set to play around with: categorial countries; time series; lat/long pairs; and, of course, nuclear explosions!

My previous machinations with the data set were all static, so I though it’d be fun to make a WarGames-esque world map animation to show who boomed where and how many booms each ended up making. The code is below (after the video). It’s commented and there are some ggplot2 tricks in there that those new to R might be interested in.

As I say in the code, I ended up tweaking `ffmpeg` parameters to get this video working on Twitter (the video file ended up being much, much smaller than the animated gif I originally toyed with making). Using `convert` from ImageMagick will quickly make a nice, local animated gif, or you can explore how to incorporate the ggplot2 frames into the `animation` package.

library(purrr)
library(dplyr)
library(tidyr)
library(sp)
library(maptools)
library(maps)
library(grid)
library(scales)
library(ggplot2)   # devtools::install_github("hadley/ggplot2")
library(ggthemes)
library(gridExtra)
library(ggalt)

# read and munge the data, being kind to github's servers
URL <- "https://raw.githubusercontent.com/data-is-plural/nuclear-explosions/master/data/sipri-report-explosions.csv"
fil <- basename(URL)
if (!file.exists(fil)) download.file(URL, fil)

read.csv(fil, stringsAsFactors=FALSE) %>%
  tbl_df() %>%
  mutate(date=as.Date(as.character(date_long), format="%Y%m%d"),
         year=as.character(year),
         yr=as.Date(sprintf("%s-01-01", year)),
         country=sub("^PAKIST$", "PAKISTAN", country)) -> dat

# doing this so we can order things by most irresponsible country to least
count(dat, country) %>%
  arrange(desc(n)) %>%
  mutate(country=factor(country, levels=unique(country))) -> booms

# Intercourse Antarctica
world_map <- filter(map_data("world"), region!="Antarctica")

scary <- "#2b2b2b" # a.k.a "slate black"
light <- "#bfbfbf" # a.k.a "off white"

proj <- "+proj=kav7" # Winkel-Tripel is *so* 2015

# In the original code I was using to play around with various themeing
# and display options this encapsulated theme_ function really helped alot
# but to do the grid.arrange with the bars it only ended up saving a teensy
# bit of typing.
#
# Also, Tungsten is ridiculously expensive but I have access via corporate
# subscriptions, so I'd suggest going with Arial Narrow vs draining your
# bank account since I really like the detailed kerning pairs but also think
# that it's just a tad too narrow. It seemed fitting for this vis, tho.

theme_scary_world_map <- function(scary="#2b2b2b", light="#8f8f8f") {
  theme_map() +
    theme(text=element_text(family="Tungsten-Light"),
          title=element_text(family="Tungsten-Semibold"),
          plot.background=element_rect(fill=scary, color=scary),
          panel.background=element_rect(fill=scary, color=scary),
          legend.background=element_rect(fill=scary),
          legend.key=element_rect(fill=scary, color=scary),
          legend.text=element_text(color=light, size=10),
          legend.title=element_text(color=light),
          axis.title=element_text(color=light),
          axis.title.x=element_text(color=light, family="Tungsten-Book", size=14),
          axis.title.y=element_blank(),
          plot.title=element_text(color=light, face="bold", size=16),
          plot.subtitle=element_text(color=light, family="Tungsten-Light",
                                     size=13, margin=margin(b=14)),
          plot.caption=element_text(color=light, family="Tungsten-ExtraLight",
                                    size=9, margin=margin(t=10)),
          plot.margin=margin(0, 0, 0, 0),
          legend.position="bottom")
}

# I wanted to see booms by unique coords
count(dat, year, country, latitude, longitude) %>%
  ungroup() %>%
  mutate(country=factor(country, levels=unique(booms$country))) -> dat_agg

years <- as.character(seq(1945, 1998, 1))

# place to hold the pngs
dir.create("booms", FALSE)

# I ended up lovingly hand-crafting ffmpeg parameters to get the animation to
# work with Twitter's posting guidelines. A plain 'old ImageMagick "convert"
# from multiple png's to animated gif will work fine for a local viewing

til <- length(years)
pb <- progress_estimated(til)
suppressWarnings(walk(1:til, function(i) {

  pb$tick()$print()
  
  # data for map
  tmp_dat <- filter(dat_agg, year<=years[i])

  # data for bars
  count(tmp_dat, country, wt=n) %>%
    arrange(desc(nn)) %>%
    mutate(country=factor(country, levels=unique(country))) %>%
    complete(country, fill=list(nn=0)) -> boom2 # this gets us all the countries on the barplot x-axis even if the had no booms yet

  gg <- ggplot()
  gg <- gg + geom_map(data=world_map, map=world_map,
                      aes(x=long, y=lat, map_id=region),
                      color=light, size=0.1, fill=scary)
  gg <- gg + geom_point(data=tmp_dat,
                        aes(x=longitude, y=latitude, size=n, color=country),
                        shape=21, stroke=0.3)

  # the "trick" here is to force the # of labeled breaks so ggplot2 doesn't
  # truncate the range on us (it's nice that way and that feature is usually helpful)
  gg <- gg + scale_radius(name="", range=c(2, 8), limits=c(1, 50),
                          breaks=c(5, 10, 25, 50),
                          labels=c("1-4", "5-9", "10-24", "25-50"))

  gg <- gg + scale_color_brewer(name="", palette="Set1", drop=FALSE)
  gg <- gg + coord_proj(proj)
  gg <- gg + labs(x=years[i], y=NULL, title="Nuclear Explosions, 1945–1998",
                  subtitle="Stockholm International Peace Research Institute (SIPRI) and Sweden's Defence Research Establishment",
                  caption=NULL)

  # order doesn't actually work but it will after I get a PR into ggplot2
  # the tweaks here let us make the legends look like we want vs just mapped
  # to the aesthetics
  gg <- gg + guides(size=guide_legend(override.aes=list(color=light, stroke=0.5)),
                    color=guide_legend(override.aes=list(alpha=1, shape=16, size=3), nrow=1))

  gg <- gg + theme_scary_world_map(scary, light)
  gg <- gg + theme(plot.margin=margin(t=6, b=-1.5, l=4, r=4))
  gg_map <- gg
  
  gg

  gg <- ggplot(boom2, aes(x=country, y=nn))
  gg <- gg + geom_bar(stat="identity", aes(fill=country), width=0.5, color=light, size=0.05)
  gg <- gg + scale_x_discrete(expand=c(0,0))
  gg <- gg + scale_y_continuous(expand=c(0,0), limits=c(0, 1100))
  gg <- gg + scale_fill_brewer(name="", palette="Set1", drop=FALSE)
  gg <- gg + labs(x=NULL, y=NULL, title=NULL, subtitle=NULL,
                  caption="Data from https://github.com/data-is-plural/nuclear-explosions")
  gg <- gg + theme_scary_world_map(scary, light)
  gg <- gg + theme(axis.text=element_text(color=light))
  gg <- gg + theme(axis.text.x=element_text(color=light, size=11, margin=margin(t=2)))
  gg <- gg + theme(axis.text.y=element_text(color=light, size=6, margin=margin(r=5)))
  gg <- gg + theme(axis.title.x=element_blank())
  gg <- gg + theme(plot.margin=margin(l=20, r=20, t=-1.5, b=5))
  gg <- gg + theme(panel.grid=element_line(color=light, size=0.15))
  gg <- gg + theme(panel.margin=margin(0, 0, 0, 0))
  gg <- gg + theme(panel.grid.major.x=element_blank())
  gg <- gg + theme(panel.grid.major.y=element_line(color=light, size=0.05))
  gg <- gg + theme(panel.grid.minor=element_blank())
  gg <- gg + theme(panel.grid.minor.x=element_blank())
  gg <- gg + theme(panel.grid.minor.y=element_blank())
  gg <- gg + theme(axis.line=element_line(color=light, size=0.1))
  gg <- gg + theme(axis.line.x=element_line(color=light, size=0.1))
  gg <- gg + theme(axis.line.y=element_blank())
  gg <- gg + theme(legend.position="none")
  gg_bars <- gg

  # dimensions arrived at via trial and error

  png(sprintf("./booms/frame_%03d.png", i), width=639.5*2, height=544*2, res=144, bg=scary)
  grid.arrange(gg_map, gg_bars, ncol=1, heights=c(0.85, 0.15), padding=unit(0, "null"), clip="on")
  dev.off()

}))

This is a follow up to a twitter-gist post & to the annotation party we’re having this week

I had not intended this to be “Annotation Week” but there was a large, positive response to my annotation “hack” post. This reaction surprised me, then someone pointed me to this link and also noted that if having to do subtitles via hacks or Illustrator annoyed me, imagine the reaction to people who actually do real work. That led me to pull up my ggplot2 fork (what, you don’t keep a fork of ggplot2 handy, too?) and work out how to augment ggplot2-proper with the functionality. It’s yet-another nod to Hadley as he designed the package so well that slipping in annotations to the label, theme & plot-building code was an actual magical experience. As I was doing this, @janschulz jumped in to add below-plot annotations to ggplot2 (which we’re calling the caption label thanks to a suggestion by @arnicas).

What’s Changed?

There are two new plot label components. The first is for subtitles that appear below the plot title. You can either do:


ggtitle("The Main Title", subtitle="A well-crafted subtitle")

or


labs(title="The Main Title", subtitle="A well-crafted subtitle")

The second is for below-plot annotations (captions), which are added via:


labs(title="Main Title", caption="Where this crazy thing game from")

These are styled via two new theme elements (both adjusted with element_text()):

  • plot.subtitle
  • plot.caption

A “casualty” of these changes is that the main plot.title is now left-justified by default (as is plot.subtitle). plot.caption is right-justified by default.

Yet-another ggplot2 Example

I have thoughts on plot typography which I’ll save for another post, but I wanted to show how to use these new components. You’ll need to devtools::install_github("hadley/ggplot2") to use them until the changes get into CRAN.

I came across this chart from the Pew Research Center on U.S. Supreme Court “wait times” this week:

supremes-pew

It seemed like a good candidate to test out the new ggplot2 additions. However, while Pew provided the chart, they did not provide data behind it. So, just for you, I used WebPlotDigitizer to encode the points (making good use of a commuter train home). Some points are (no doubt) off by one or two, but precision was not necessary for this riff. The data (and code) are in this gist. First the data.


library(ggplot2)

dat <- read.csv("supreme_court_vacancies.csv", col.names=c("year", "wait"))

Now, we want to reproduce the original chart "theme" pretty closely, so I've done quite a bit of styling outside of the subtitle/caption. One thing we can take care of right away is how to only label every other tick:

xlabs <- seq(1780, 2020, by=10)
xlabs[seq(2, 24, by=2)]  <-  " "

Now we setup the caption. It's long, so we need to wrap it (you need to play with the number of characters value to suit your needs). There's a Shiny Gadget (which is moving to the ggThemeAssist package) to help with this.


caption <- "Note: Vacancies are counted as the number of days between a justice's death, retirement or resignation and the successor justice's swearing in (or commissioning in the case of a recess appointment) as a member of the court.Sources: U.S. Senate, 'Supreme Court Nominations, present-1789'; Supreme Court, 'Members of the Supreme Court of the United States'; Pew Research Center calculations"
caption <- paste0(strwrap(caption, 160), sep="", collapse="\n")
# NOTE: you could probably just use caption <- label_wrap_gen(160)(caption) instead

We're going to try to fully reproduce all the annotations, so here are the in-plot point labels. (Adding the lines is an exercise left to the reader.)


annot <- read.table(text=
"year|wait|just|text
1848|860|0|Robert Cooper Grier was sworn in Aug 10, 1846,
841 days after the death of Henry Baldwin 1969|440|1|Henry Blackmun was sworn
in June 9, 1970, 391 days
after Abe Fortas resigned. 1990|290|0|Anthony Kennedy
was sworn in Feb.
18, 1988, 237
days after Lewis
Powell retired.", sep="|", header=TRUE, stringsAsFactors=FALSE) annot$text <- gsub("
", "\n", annot$text)

Now the fun begins.


gg <- ggplot()
gg <- gg + geom_point(data=dat, aes(x=year, y=wait))

We'll add the y-axis "title" to the inside of the plot:


gg <- gg + geom_label(aes(x=1780, y=900, label="days"),
                      family="OpenSans-CondensedLight",
                      size=3.5, hjust=0, label.size=0, color="#2b2b2b")

Now, we add our lovingly hand-crafted in-plot annotations:


gg <- gg + geom_label(data=annot, aes(x=year, y=wait, label=text, hjust=just),
                      family="OpenSans-CondensedLight", lineheight=0.95,
                      size=3, label.size=0, color="#2b2b2b")

Then, tweak the axes:


gg <- gg + scale_x_continuous(expand=c(0,0),
                              breaks=seq(1780, 2020, by=10),
                              labels=xlabs, limits=c(1780,2020))
gg <- gg + scale_y_continuous(expand=c(0,10),
                              breaks=seq(100, 900, by=100),
                              limits=c(0, 1000))

Thanks to Hadley's package design & Jan's & my additions, this is all you need to do to add the subtitle & caption:


gg <- gg + labs(x=NULL, y=NULL,
                title="Lengthy Supreme Court vacancies are rare now, but weren't always",
                subtitle="Supreme Court vacancies, by duration",
                caption=caption)

Well, perhaps not all since we need to style this puppy. You'll either need to install the font from Google Fonts or sub out the fonts for something you have.


gg <- gg + theme_minimal(base_family="OpenSans-CondensedLight")
# light, dotted major y-grid lines only
gg <- gg + theme(panel.grid=element_line())
gg <- gg + theme(panel.grid.major.y=element_line(color="#2b2b2b", linetype="dotted", size=0.15))
gg <- gg + theme(panel.grid.major.x=element_blank())
gg <- gg + theme(panel.grid.minor.x=element_blank())
gg <- gg + theme(panel.grid.minor.y=element_blank())
# light x-axis line only
gg <- gg + theme(axis.line=element_line())
gg <- gg + theme(axis.line.x=element_line(color="#2b2b2b", size=0.15))
# tick styling
gg <- gg + theme(axis.ticks=element_line())
gg <- gg + theme(axis.ticks.x=element_line(color="#2b2b2b", size=0.15))
gg <- gg + theme(axis.ticks.y=element_blank())
gg <- gg + theme(axis.ticks.length=unit(5, "pt"))
# breathing room for the plot
gg <- gg + theme(plot.margin=unit(rep(0.5, 4), "cm"))
# move the y-axis tick labels over a bit
gg <- gg + theme(axis.text.y=element_text(margin=margin(r=-5)))
# make the plot title bold and modify the bottom margin a bit
gg <- gg + theme(plot.title=element_text(family="OpenSans-CondensedBold", margin=margin(b=15)))
# make the subtitle italic 
gg <- gg + theme(plot.subtitle=element_text(family="OpenSans-CondensedLightItalic"))
# make the caption smaller, left-justified and give it some room from the main part of the panel
gg <- gg + theme(plot.caption=element_text(size=8, hjust=0, margin=margin(t=15)))
gg

That generates:

All the annotations go with the code. No more tricks, hacks or desperate calls for help on StackOverflow!

Now, this does add two new elements to the underlying gtable that gets built, so some other StackOverflow (et al) hacks may break if they don't use names (these elements are named in the gtable just like their ggplot2 names). We didn't muck with the widths/columns at all, so all those hacks (mostly for multi-plot alignment) should still work.

All the code/data is (again) in this gist.

>UPDATE: time spent per task factor order was wrong before. now fixed.

I caught this tweet today:

The WSJ folks usually do a great job, but this was either rushed or not completely thought through. There’s no way you’re going to be able to do any real comparisons between the segments across pies and direct pie % labels kinda mean they should have just made a table if they were going to phone it in.

Despite the fact that today is Pi[e] Day, these pies need to go.

If the intent was to primarily allow comparison of hours in-task, leaving some ability to compare the same time category across tasks, then bars are probably the way to go (you could do a parallel coordinates plot, but those looks like tangled guitar strings to me, so I’ll stick with bars). Here’s one possible alternative using R & ggplot2. Since I provide the data, please link to your own creations as I’d love to see how others would represent the data.

NOTE: I left direct bar labels off deliberately. My view is that (a) this is designed to be a relative comparison vs precise comparison & (b) it’s survey data and if we’re going to add #’s I’d feel compelled to communicate margin of error, etc. I don’t think that’s necessary.

library(ggplot2)
library(grid)
library(scales)
library(hrbrmisc) # devtools::install_github("hrbrmstr/hrbrmisc")
library(tidyr)
 
dat <- read.table(text=
"Task|less_than_one_hour_per_week|one_to_four_hours_per_week|one_to_three_hours_a_day|four_or_more_hours_a_day
Basic exploratory data analysis|11|32|46|12
Data cleaning|19|42|31|7
Machine learning, statistics|34|29|27|10
Creating visualizations|23|41|29|7
Presenting analysis|27|47|20|6
Extract, transform, load|43|32|20|5", sep="|", header=TRUE, stringsAsFactors=FALSE)
 
amount_trans <- c("less_than_one_hour_per_week"="<1 hr/\nwk", 
                  "one_to_four_hours_per_week"="1-4 hrs/\nwk", 
                  "one_to_three_hours_a_day"="1-3 hrs/\nday", 
                  "four_or_more_hours_a_day"="4+ hrs/\nday")
 
dat <- gather(dat, amount, value, -Task)
dat$value <- dat$value / 100
dat$amount <- factor(amount_trans[dat$amount], levels=amount_trans)
 
title_trans <- c("Basic exploratory data analysis"="Basic exploratory\ndata analysis", 
                 "Data cleaning"="Data\ncleaning", 
                 "Machine learning, statistics"="Machine learning,\nstatistics", 
                 "Creating visualizations"="Creating\nvisualizations", 
                 "Presenting analysis"="Presenting\nanalysis", 
                 "Extract, transform, load"="Extract,\ntransform, load")
 
dat$Task <-factor(title_trans[dat$Task], levels=title_trans)
 
gg <- ggplot(dat, aes(x=amount, y=value, fill=amount))
gg <- gg + geom_bar(stat="identity", width=0.75, color="#2b2b2b", size=0.05)
gg <- gg + scale_y_continuous(expand=c(0,0), labels=percent, limits=c(0, 0.5))
gg <- gg + scale_x_discrete(expand=c(0,1))
gg <- gg + scale_fill_manual(name="", values=c("#a6cdd9", "#d2e4ee", "#b7b079", "#efc750"))
gg <- gg + facet_wrap(~Task, scales="free")
gg <- gg + labs(x=NULL, y=NULL, title="Where Does the Time Go?")
gg <- gg + theme_hrbrmstr(grid="Y", axis="x", plot_title_margin=9)
gg <- gg + theme(panel.background=element_rect(fill="#efefef", color=NA))
gg <- gg + theme(strip.background=element_rect(fill="#858585", color=NA))
gg <- gg + theme(strip.text=element_text(family="OpenSans-CondensedBold", size=12, color="white", hjust=0.5))
gg <- gg + theme(panel.margin.x=unit(1, "cm"))
gg <- gg + theme(panel.margin.y=unit(0.5, "cm"))
gg <- gg + theme(legend.position="none")
gg <- gg + theme(panel.grid.major.y=element_line(color="#b2b2b2"))
gg <- gg + theme(axis.text.x=element_text(margin=margin(t=-10)))
gg <- gg + theme(axis.text.y=element_text(margin=margin(r=-10)))
 
ggplot_with_subtitle(gg, 
                     "The amount of time spent on various tasks by surveyed non-managers in data-science positions.",
                     fontfamily="OpenSans-CondensedLight", fontsize=12, bottom_margin=16)

RStudioScreenSnapz018

It’s been a while since I’ve updated my [metricsgraphics package](https://cran.r-project.org/web/packages/metricsgraphics/index.html). The hit list for changes includes:

– Fixes for the new ggplot2 release (metricsgraphics uses the `movies` data set which is now in ggplot2movies)
– Updated all javascript libraries to the most recent versions
– Borrowed the ability to add CSS rules to a widget from taucharts (`mjs_add_css_rule`)
– Added a metricsgraphics plugin to enable line chart region annotation (`mjs_annotate_region`)
– Enabled explicit coloring line/area charts (it was a new feature in the underlying Metrics-Graphics library)
– You can use bare or quoted names when specifying the x & y accessors and can also use a variable name
– You can now use the metricsgraphics title & description capabilities, but doing so voids any predictable/specified widget height/width and the description functionality is really only suited for bootstrap templates

I think all that can be demonstrated in the following snippet:

library(metricsgraphics)
 
dat <- read.csv("http://real-chart.finance.yahoo.com/table.csv?s=AAPL&a=07&b=9&c=1996&d=11&e=21&f=2015&g=d&ignore=.csv",
                stringsAsFactors=FALSE)
 
DATE <- "Date"
 
dat %>%
  filter(Date>="2008-01-01") %>% 
  mjs_plot(DATE, y="Low", title="AAPL Stock (2008-Present)", width=800, height=500) %>% 
  mjs_line(color="#6a3d9a") %>% 
  mjs_add_line(High, color="#ff7f00") %>% 
  mjs_axis_x(xax_format="date") %>% 
  mjs_add_css_rule("{{ID}} .blk { fill:black }") %>%
  mjs_annotate_region("2013-01-01", "2013-12-31", "Volatility", "blk") %>% 
  mjs_add_marker("2014-06-09", "Split") %>% 
  mjs_add_marker("2012-09-12", "iPhone 5") %>% 
  mjs_add_legend(c("Low", "High"))

NOTE: I’m still trying to figure out why WebKit on Safari renders the em dashes and Chrome does not.