tm_legend(frame = FALSE) doesn't remove legend's frame when used inside tm_raster()

[shringi]

I think tm_legend(frame = FALSE) inside tm_raster() doesn't work as expected, however, it works as usual for tm_polygon().
It starts to work okay when a map has both tm_raster() and tm_polygon() layers added in a single map.

The following is an example I could reproduce.

library(tmap)

packageVersion("tmap")
#> [1] '4.1'
packageDate("tmap")
#> [1] "2025-05-25"
tmap_options(component.autoscale = FALSE)

The following plot doesn’t remove the legend frame when tm_legend(frame = FALSE) inside tm_raster()

rast_Frame_F <- tm_shape(land) +
  tm_raster("trees", 
            col.legend = tm_legend(frame = F, title = "Trees \n(Rast Frame = F)"))

rast_Frame_F

However, the option works when used inside the tm_polygon()

poly_Frame_F <- tm_shape(World) +
  tm_borders(col = "area", 
             col.legend = tm_legend(frame = F, title = "Area \n(Poly Frame = F)"))

poly_Frame_F
#> [tip] Consider a suitable map projection, e.g. by adding `+ tm_crs("auto")`.
#> This message is displayed once per session.

Frame appears as expected when tm_legend(frame = TRUE)

rast_Frame_T <- tm_shape(land) +
  tm_raster("trees", 
            col.legend = tm_legend(frame = T, title = "Trees \n(Rast Frame = T)"))
poly_Frame_T <- tm_shape(World) +
  tm_borders(col = "area", 
             col.legend = tm_legend(frame = T, title = "Area \n(Poly Frame = T)"))

However, the options start to work according to the first map layer setting of tm_legen() when the two layers are combined. Examples are as follows.

poly_Frame_T + rast_Frame_F # T

poly_Frame_F + rast_Frame_T # F

rast_Frame_T + poly_Frame_F # T

rast_Frame_F + poly_Frame_T # F

^{Created on 2025-05-25 with reprex v2.1.1}

Session info

sessionInfo()
#> R version 4.5.0 (2025-04-11 ucrt)
#> Platform: x86_64-w64-mingw32/x64
#> Running under: Windows 11 x64 (build 22631)
#> 
#> Matrix products: default
#>   LAPACK version 3.12.1
#> 
#> locale:
#> [1] LC_COLLATE=English_India.utf8  LC_CTYPE=English_India.utf8   
#> [3] LC_MONETARY=English_India.utf8 LC_NUMERIC=C                  
#> [5] LC_TIME=English_India.utf8    
#> 
#> time zone: Asia/Calcutta
#> tzcode source: internal
#> 
#> attached base packages:
#> [1] stats     graphics  grDevices utils     datasets  methods   base     
#> 
#> other attached packages:
#> [1] tmap_4.1
#> 
#> loaded via a namespace (and not attached):
#>  [1] s2_1.1.9                class_7.3-23            lwgeom_0.2-14          
#>  [4] KernSmooth_2.23-26      lattice_0.22-7          digest_0.6.37          
#>  [7] magrittr_2.0.3          evaluate_1.0.3          grid_4.5.0             
#> [10] RColorBrewer_1.1-3      fastmap_1.2.0           e1071_1.7-16           
#> [13] leafsync_0.1.0          DBI_1.2.3               crosstalk_1.2.1        
#> [16] viridisLite_0.4.2       cols4all_0.8            XML_3.99-0.18          
#> [19] codetools_0.2-20        abind_1.4-8             cli_3.6.5              
#> [22] rlang_1.1.6             units_0.8-7             tmaptools_3.2          
#> [25] reprex_2.1.1            base64enc_0.1-3         withr_3.0.2            
#> [28] yaml_2.3.10             leaflegend_1.2.1        tools_4.5.0            
#> [31] raster_3.6-32           parallel_4.5.0          maptiles_0.10.0        
#> [34] colorspace_2.1-1        spacesXYZ_1.5-1         logger_0.4.0           
#> [37] R6_2.6.1                png_0.1-8               proxy_0.4-27           
#> [40] lifecycle_1.0.4         classInt_0.4-11         leaflet_2.2.2          
#> [43] leaflet.providers_2.0.0 fs_1.6.6                htmlwidgets_1.6.4      
#> [46] terra_1.8-50            data.table_1.17.2       glue_1.8.0             
#> [49] Rcpp_1.0.14             sf_1.0-21               xfun_0.52              
#> [52] rstudioapi_0.17.1       knitr_1.50              dichromat_2.0-0.1      
#> [55] htmltools_0.5.8.1       rmarkdown_2.29          leafem_0.2.4           
#> [58] wk_0.9.4                compiler_4.5.0          sp_2.2-0               
#> [61] stars_0.6-8

[mtennekes]

Thx @shringi for this clear report.

It seems to be an issue with tm_raster() only. I'll look into it.

You can set the frame color to missing to make it work for the time being:

tm_shape(land) +
	tm_raster("trees", 
			  col.legend = tm_legend(frame = FALSE, frame.color = NA))