better error messages

[mtennekes]

tm_shape(World)


tm_shape(World) +  tm_fill("pop_est_dens", fill.scale = tm_scale_intervals(c("yellow", "orange", "red"))) + tm_facets(by = "continent")

tm_shape(World) +  tm_fill("pop_est_dens",
fill.scale = tm_scale_intervals(c("yellow", "orange", "red"))) + tm_facets(by = "continent")

[olivroy]

I have a suggestion.

While trying to convert my code to v4, I encountered the following:

v3 code detected: as of tmap v4, tm_legend should be specified per visual variable (e.g. with the argument fill.legend of tm_polygons

Here is what I would suggest instead:

v3 code detected: as of tmap v4, the legend should be specified for each visual variable (e.g. with fill.legend = tm_legend() inside tm_polygons to control the legend of fill for polygons.

+ v3 code detected: as of tmap v4, the legend should be specified for each visual variable (e.g. with `fill.legend = tm_legend()` inside tm_polygons to control the legend of `fill` for polygons.
- v3 code detected: as of tmap v4, tm_legend should be specified per visual variable (e.g. with the argument fill.legend of tm_polygons

[olivroy]

tm_shape(World)

• 1 on this one. in v3, we had Error: no layer elements defined after tm_shape, which was more helpful than the current one

[mtennekes]

tm_shape(World)

• 1 on this one. in v3, we had Error: no layer elements defined after tm_shape, which was more helpful than the current one

Improved! It doesn't cause an error, because a single tm_shape may be handy:

tm_shape(World)
#> [nothing to show] no data layers defined after tm_shape

# without data layers, but with an aux layer
tm_shape(World) + tm_grid() # should this cause a warning? It may be on purpose...

# a single tm_shape to set crs and bbox:
tm_shape(NLD_muni) + tm_shape(World) + tm_polygons()

# with facets...
tm_shape(NLD_muni) + tm_shape(World) + tm_polygons() + tm_facets(by = "continent")

# ... the is.main argument can be used:
tm_shape(NLD_muni) + tm_shape(World, is.main = TRUE) + tm_polygons() + tm_facets(by = "continent")

^{Created on 2024-05-08 with reprex v2.1.0}