New ggplot2 map machinations
hrbrmstr
library(ggplot2)
library(ggalt)
library(maptools)
library(dplyr)Show which version of ggplot (et al) we’re using
devtools::session_info()## Session info --------------------------------------------------------------## setting value
## version R version 3.3.2 RC (2016-10-26 r71594)
## system x86_64, darwin13.4.0
## ui X11
## language (EN)
## collate en_US.UTF-8
## tz America/New_York
## date 2016-12-30## Packages ------------------------------------------------------------------## package * version date source
## ash 1.0-15 2015-09-01 CRAN (R 3.3.0)
## assertthat 0.1 2013-12-06 CRAN (R 3.3.0)
## colorspace 1.3-2 2016-12-14 cran (@1.3-2)
## DBI 0.5-1 2016-09-10 CRAN (R 3.3.0)
## devtools 1.12.0 2016-06-24 CRAN (R 3.3.0)
## digest 0.6.10 2016-08-02 CRAN (R 3.3.0)
## dplyr * 0.5.0.9000 2016-11-08 local
## evaluate 0.10 2016-10-11 cran (@0.10)
## extrafont 0.17 2014-12-08 CRAN (R 3.3.0)
## extrafontdb 1.0 2012-06-11 CRAN (R 3.3.0)
## foreign 0.8-67 2016-09-13 CRAN (R 3.3.2)
## ggalt * 0.3.1.9000 2016-12-05 local (hrbrmstr/ggalt@d014b9e)
## ggplot2 * 2.2.0.9000 2016-12-05 Github (hadley/ggplot2@f6f9f9d)
## gtable 0.2.0 2016-02-26 CRAN (R 3.3.0)
## htmltools 0.3.5 2016-03-21 CRAN (R 3.3.0)
## KernSmooth 2.23-15 2015-06-29 CRAN (R 3.3.2)
## knitr 1.15.6 2016-12-15 Github (yihui/knitr@849f2d0)
## lattice 0.20-34 2016-09-06 CRAN (R 3.3.2)
## lazyeval 0.2.0 2016-06-12 CRAN (R 3.3.0)
## magrittr 1.5 2014-11-22 CRAN (R 3.3.0)
## maps 3.1.1 2016-07-27 CRAN (R 3.3.0)
## maptools * 0.8-39 2016-01-30 CRAN (R 3.3.0)
## MASS 7.3-45 2016-04-21 CRAN (R 3.3.2)
## memoise 1.0.0 2016-01-29 CRAN (R 3.3.0)
## munsell 0.4.3 2016-02-13 CRAN (R 3.3.0)
## plyr 1.8.4 2016-06-08 CRAN (R 3.3.0)
## proj4 1.0-8 2012-08-05 CRAN (R 3.3.0)
## R6 2.2.0 2016-10-05 cran (@2.2.0)
## RColorBrewer 1.1-2 2014-12-07 CRAN (R 3.3.0)
## Rcpp 0.12.8 2016-11-17 cran (@0.12.8)
## rmarkdown 1.2 2016-11-21 CRAN (R 3.3.2)
## rprojroot 1.0-2 2016-03-28 CRAN (R 3.3.0)
## Rttf2pt1 1.3.4 2016-05-19 CRAN (R 3.3.0)
## scales 0.4.1.9000 2016-12-05 Github (hadley/scales@89c2a2f)
## sp * 1.2-3 2016-04-14 CRAN (R 3.3.0)
## stringi 1.1.2 2016-10-01 cran (@1.1.2)
## stringr 1.1.0 2016-08-19 cran (@1.1.0)
## tibble 1.2 2016-08-26 cran (@1.2)
## withr 1.0.2 2016-06-20 CRAN (R 3.3.0)
## yaml 2.1.14 2016-11-12 cran (@2.1.14)Get some built-in map data
world <- map_data("world")Unlike every other geom, geom_map() stands out with different behaviour O_o
ggplot() +
geom_map(data=world, map=world, aes(map_id=region))
What the…
It’s due to the fact that it no longer accepts x & y aesthetic mappings. But…it really does still take them. It just coughs up some blood while doing so.
ggplot() +
geom_map(data=world, map=world, aes(x=long, y=lat, map_id=region))## Warning: Ignoring unknown aesthetics: x, y
The new man page for geom_map() says to use expand_limits()
ggplot() +
geom_map(data=world, map=world, aes(map_id=region)) +
expand_limits(x=world$long, y=world$lat)
All that does is build a data frame for you and then call geom_blank(), so we could just do this instead:
ggplot() +
geom_blank(data=world, aes(x=long, y=lat)) +
geom_map(data=world, map=world, aes(map_id=region))
Fundamentally, it’s just a matter of getting x & y into the resultant ggplot2 objects so it can pass real values to the grid graphics calls.
The example below was a bit more elegant but that failed to work in a knitr context, so it’s very “ugh” now.
ggplot() + geom_map(data=world, map=world, aes(map_id=region)) -> g1
ggplot() + geom_map(data=world, map=world, aes(x=long, y=lat, map_id=region)) -> g2
ggplot() + geom_map(data=world, map=world, aes(map_id=region)) + expand_limits(x=world$long, y=world$lat) -> g3
ggplot() + geom_blank(data=world, aes(x=long, y=lat)) + geom_map(data=world, map=world, aes(map_id=region)) -> g4
gb1 <- ggplot_build(g1)
gb2 <- ggplot_build(g2)
gb3 <- ggplot_build(g3)
gb4 <- ggplot_build(g4)We can look at the data built for each of those
No x or y aes in geom_map() and no expand_limits() or geom_blank()
glimpse(gb1$data)## List of 1
## $ :'data.frame': 99338 obs. of 8 variables:
## ..$ map_id : chr [1:99338] "Aruba" "Aruba" "Aruba" "Aruba" ...
## ..$ PANEL : int [1:99338] 1 1 1 1 1 1 1 1 1 1 ...
## ..$ group : atomic [1:99338] 12 12 12 12 12 12 12 12 12 12 ...
## .. ..- attr(*, "n")= int 252
## ..$ colour : chr [1:99338] "NA" "NA" "NA" "NA" ...
## ..$ fill : chr [1:99338] "grey20" "grey20" "grey20" "grey20" ...
## ..$ size : num [1:99338] 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 ...
## ..$ linetype: num [1:99338] 1 1 1 1 1 1 1 1 1 1 ...
## ..$ alpha : logi [1:99338] NA NA NA NA NA NA ...The polygons have no x or y variables in ^^ so they can’t be drawn :-( Has x and y aes in geom_map() but no expand_limits() or geom_blank()
glimpse(gb2$data)## List of 1
## $ :'data.frame': 99338 obs. of 10 variables:
## ..$ x : num [1:99338] -69.9 -69.9 -69.9 -70 -70.1 ...
## ..$ y : num [1:99338] 12.5 12.4 12.4 12.5 12.5 ...
## ..$ map_id : chr [1:99338] "Aruba" "Aruba" "Aruba" "Aruba" ...
## ..$ PANEL : int [1:99338] 1 1 1 1 1 1 1 1 1 1 ...
## ..$ group : atomic [1:99338] 12 12 12 12 12 12 12 12 12 12 ...
## .. ..- attr(*, "n")= int 252
## ..$ colour : chr [1:99338] "NA" "NA" "NA" "NA" ...
## ..$ fill : chr [1:99338] "grey20" "grey20" "grey20" "grey20" ...
## ..$ size : num [1:99338] 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 ...
## ..$ linetype: num [1:99338] 1 1 1 1 1 1 1 1 1 1 ...
## ..$ alpha : logi [1:99338] NA NA NA NA NA NA ...Old school ggplot2 behaviour in ^^ (one data.frame with everyting including x & y). No x or y aes in geom_map() but has expand_limits() [which is really geom_blank()]
glimpse(gb3$data)## List of 2
## $ :'data.frame': 99338 obs. of 8 variables:
## ..$ map_id : chr [1:99338] "Aruba" "Aruba" "Aruba" "Aruba" ...
## ..$ PANEL : int [1:99338] 1 1 1 1 1 1 1 1 1 1 ...
## ..$ group : atomic [1:99338] 12 12 12 12 12 12 12 12 12 12 ...
## .. ..- attr(*, "n")= int 252
## ..$ colour : chr [1:99338] "NA" "NA" "NA" "NA" ...
## ..$ fill : chr [1:99338] "grey20" "grey20" "grey20" "grey20" ...
## ..$ size : num [1:99338] 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 ...
## ..$ linetype: num [1:99338] 1 1 1 1 1 1 1 1 1 1 ...
## ..$ alpha : logi [1:99338] NA NA NA NA NA NA ...
## $ :'data.frame': 99338 obs. of 4 variables:
## ..$ x : num [1:99338] -69.9 -69.9 -69.9 -70 -70.1 ...
## ..$ y : num [1:99338] 12.5 12.4 12.4 12.5 12.5 ...
## ..$ PANEL: int [1:99338] 1 1 1 1 1 1 1 1 1 1 ...
## ..$ group: int [1:99338] -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 ...That ^^ gives us x and y, but in a second data.frame with PANEL (thankfully the same) and a different group. No x or y aes in geom_map() but has geom_blank() [which expand_limits() just wraps]
glimpse(gb4$data)## List of 2
## $ :'data.frame': 99338 obs. of 4 variables:
## ..$ x : num [1:99338] -69.9 -69.9 -69.9 -70 -70.1 ...
## ..$ y : num [1:99338] 12.5 12.4 12.4 12.5 12.5 ...
## ..$ PANEL: int [1:99338] 1 1 1 1 1 1 1 1 1 1 ...
## ..$ group: int [1:99338] -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 ...
## $ :'data.frame': 99338 obs. of 8 variables:
## ..$ map_id : chr [1:99338] "Aruba" "Aruba" "Aruba" "Aruba" ...
## ..$ PANEL : int [1:99338] 1 1 1 1 1 1 1 1 1 1 ...
## ..$ group : atomic [1:99338] 12 12 12 12 12 12 12 12 12 12 ...
## .. ..- attr(*, "n")= int 252
## ..$ colour : chr [1:99338] "NA" "NA" "NA" "NA" ...
## ..$ fill : chr [1:99338] "grey20" "grey20" "grey20" "grey20" ...
## ..$ size : num [1:99338] 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 ...
## ..$ linetype: num [1:99338] 1 1 1 1 1 1 1 1 1 1 ...
## ..$ alpha : logi [1:99338] NA NA NA NA NA NA ...That ^^ also gives us x and y, but in a second data.frame with PANEL (thankfully the same) and a different group.
I don’t do enough mapping in the $DAYJOB to know if the different groups are going to cause issues for folks, nor have I looked in the ggplot2 github issues log. ### Thankfully, projections still work in the new paradigm
us <- map_data("usa")
ggplot() +
geom_blank(data=us, aes(x=long, y=lat)) +
geom_map(data=us, map=us, aes(map_id=region)) +
coord_map("polyconic")
Including the more versatile ggalt::coord_proj()
ggplot() +
geom_blank(data=us, aes(x=long, y=lat)) +
geom_map(data=us, map=us, aes(map_id=region)) +
coord_proj(albersusa::us_laea_proj)