Legends and titles for RasterStacks in view mode

[see24]

This is a couple of related issues when plotting RasterStacks in "view" mode.

1. There are two legends in view mode when as.layers = TRUE. This makes the plot quite crowded and is not helpful when the legends are the same. I tried free.scales.raster = FALSE thinking that might remove the second legend but it did not.

library(tmap)
library(raster)

data(land)

land_rast <- as(land, "Raster")

cover_cls <- land_rast$cover_cls

cover_cls2 <- reclassify(cover_cls, matrix(c(7, 8), ncol = 2))

stk <- stack(cover_cls, cover_cls2)

tm_examp <- tm_shape(stk,) +
  tm_raster(style = "cat")

tm_examp

# has two legends that are the same (including the titles)
cur_mode <- tmap_mode("view")

tm_examp+tm_facets(as.layers = TRUE, free.scales.raster = FALSE)

2. it is not clear in the documentation how to name the layers when using a RasterStack. In tm_shape it says that name determines the name of the layer in view mode but it does not work for a raster stack. Using group in tm_raster seems to work but it gives a warning.

tm_examp2 <- tm_shape(stk, name = c("name1", "name2")) +
  tm_raster(style = "cat", title = c("title1", "title2"))+
  tm_layout(title = NA)+
  tm_facets(as.layers = TRUE, free.scales.raster = FALSE)

tm_examp2
# name has no effect 

tm_examp3 <- tm_shape(stk) +
  tm_raster(style = "cat", title = c("title1", "title2"), 
            group = c("group1", "group2"))+
  tm_layout(title = NULL)+
  tm_facets(as.layers = TRUE, free.scales.raster = FALSE)

tm_examp3
# group works but get this warning message 4 times
# 1: In if (is.na(gpl$raster.group)) { :
#     the condition has length > 1 and only the first element will be used

3. I also can't figure out how to get rid of the global title in the top left in view mode. I tried NA and NULL above but they did not work.

tm_shape(stk) +
  tm_raster(style = "cat", title = c("title1", "title2"), 
            group = c("group1", "group2"))+
  tm_layout(title = "")+
  tm_facets(as.layers = TRUE, free.scales.raster = FALSE)

tm_shape(stk) +
  tm_raster(style = "cat", title = c("title1", "title2"), 
            group = c("group1", "group2"))+
  tm_layout(title = "globaltitle")+
  tm_facets(as.layers = TRUE, free.scales.raster = FALSE)

tmap_mode(cur_mode)

[see24]

Re 2.: I just noticed that using group does not actually work. It changes the names in the layer list but when you uncheck the layers it has no effect.

[mtennekes]

Thanks for reporting these issues @see24

tmap is very buggy in this application. I will use this example in the development of tmap4.

Ideally, there should be a set of radio buttons rather than independent check boxes to select one layer.

@tim-salabim How would you tackle this (and the other issues) in mapview?

[see24]

Just a heads up that what used to produce a warning message now produces an error: Error in if (is.na(gpl$raster.group)) { : the condition has length > 1

For me this meant that maps in a shiny app just didn't show up and I wasn't seeing the error message. Not sure if that was a tmap:renderTmap issue or a shiny one but it made it quite confusing so I thought I would mention in case others have this issue