How to change the attribute table popup/hover text in a plotly map

Question

I am trying to make an interactive plotly map from a shapefile, with a hover/tooltip that shows some information.

Currently when I hover over an area on the map it only gives the information for VAR1 (A,B,C,D) rather than the information in DATA$HOVER

The map (Called NUTS1 in my code) is obtained from: http://geoportal.statistics.gov.uk/datasets/nuts-level-1-january-2018-full-clipped-boundaries-in-the-united-kingdom)

I do not have access to SF.

sessionInfo()
R version 3.4.0 Patched (2017-05-31 r72750)
Platform: x86_64-w64-mingw32/x64 (64-bit)
Running under: Windows 7 x64 (build 7601) Service Pack 1

packageVersion("plotly")
[1] ‘4.7.1’

packageVersion("ggplot2")
[1] ‘2.2.1’

DATA <- c(NA)
DATA$NUTS1 <- c("UKC","UKD","UKE","UKF","UKG","UKH","UKI","UKJ","UKK","UKL","UKM",
"UKN")
DATA$VAR1  <- c("D","D","A","D","A","C","B","C","B","C","B","A")
DATA$VAR2  <- c("8","4","1","10","4","7","5","1","8","6","3","8")
DATA$VAR3  <- c("1","2","3","4","5","6","7","8","9","10","11","12")
NUTS1 <- readOGR(dsn = 
          "NUTS_Level_1_January_2018_Full_Clipped_Boundaries_in_the_United_Kingdom",
                 layer = 
          "NUTS_Level_1_January_2018_Full_Clipped_Boundaries_in_the_United_Kingdom")
NUTS1 <- fortify(NUTS1, region = "nuts118cd")
DATA$HOVER <- with(DATA, paste(NUTS1, "<br>", VAR1, "<br>", VAR2, "<br>", VAR3))

p <- ggplot(data = DATA, text = HOVER) + 
  geom_map(data = DATA, aes(map_id = NUTS1, fill = VAR1), map = NUTS1) + 
  expand_limits(x = NUTS1$long, y = NUTS1$lat)

p <- ggplotly(p, tooltip = "text")

Answer 1

I think, first of all, your DATA object should be a data.frame (from your code I get a list, which is no accepted by the ggplot() function).

Then, try to map the column HOVER into the text aesthetic in geom_map() and not in ggplot().

Also, in your DATA data.frame, rename the column NUTS1 to id, so that it matches the column name id from NUTS1 data.frame obtained with fortify (you see that this is important from the examples found in help(geom_map)).

library(ggplot2)
library(plotly)
library(rgdal)

DATA <- data.frame(id = c("UKC","UKD","UKE","UKF","UKG","UKH","UKI","UKJ","UKK","UKL","UKM","UKN"),
                   VAR1 = c("D","D","A","D","A","C","B","C","B","C","B","A"),
                   VAR2 = c("8","4","1","10","4","7","5","1","8","6","3","8"),
                   VAR3 = 1:12)
DATA$HOVER <- with(DATA, paste(id, "<br>", VAR1, "<br>", VAR2, "<br>", VAR3))

NUTS1 <- readOGR(dsn = "NUTS_Level_1_January_2018_Full_Clipped_Boundaries_in_the_United_Kingdom",
                 layer = "NUTS_Level_1_January_2018_Full_Clipped_Boundaries_in_the_United_Kingdom")
NUTS1 <- fortify(NUTS1, region = "nuts118cd")

p <- ggplot(data = DATA) + 
  geom_map(aes(map_id = id, fill = VAR1, text = HOVER), map = NUTS1) +
  expand_limits(x = NUTS1$long, y = NUTS1$lat)

p2 <- ggplotly(p)
p2

---

Note that, interactive maps are more straightforward to make with the mapview package. For your particular issue, check mapview popups. Here is an attempt with mapview:

library(mapview)
library(rgdal)

NUTS1 <- readOGR(dsn = "NUTS_Level_1_January_2018_Full_Clipped_Boundaries_in_the_United_Kingdom",
                 layer = "NUTS_Level_1_January_2018_Full_Clipped_Boundaries_in_the_United_Kingdom")

DATA <- data.frame(NUTS1 = c("UKC","UKD","UKE","UKF","UKG","UKH","UKI","UKJ","UKK","UKL","UKM","UKN"),
                   VAR1 = c("D","D","A","D","A","C","B","C","B","C","B","A"),
                   VAR2 = c("8","4","1","10","4","7","5","1","8","6","3","8"),
                   VAR3 = 1:12)
# merge DATA with the SpatialPolygonsDataFrame NUTS1
nuts <- merge(x = NUTS1, y = DATA, by.x = "nuts118cd", by.y = "NUTS1")

mapview(nuts, popup = popupTable(nuts, zcol = c("nuts118cd", "VAR1", "VAR2", "VAR3")))

To fill by VAR1, you need to follow this example and call zcol = "VAR1" in mapview, like:

mapview(nuts, zcol = "VAR1", 
        popup = popupTable(nuts, zcol = c("nuts118cd", "VAR1", "VAR2", "VAR3")))