一个简单的plotRGB会生成原始图片，而使用tmap绘制只会生成一张蓝色阴影的图片。我做错了什么？
原始图片
蓝色阴影的图片
代码片段：
library(raster)
library(tmap)
library(rnaturalearth)
ne_download(scale = 50, type = 'HYP_50M_SR_W', category = 'raster', destdir = getwd())
rst <- brick("HYP_50M_SR_W/HYP_50M_SR_W.tif")
plotRGB(rst) # works
tmap_mode("plot")
tm_shape(rst) + tm_rgb() # does not work
使用的工具：R版本3.5.1，RStudio版本1.1.456，tmap版本2.1-1，raster版本2.6-7，rnaturalearth版本0.1.0
它可能正在运行，但请注意警告：
library(raster)
#> Loading required package: sp
library(tmap)
#> Warning: package 'tmap' was built under R version 3.5.2
library(rnaturalearth)
#> Warning: package 'rnaturalearth' was built under R version 3.5.2
ne_download(scale = 50, type = 'HYP_50M_SR_W', category = 'raster', destdir = getwd())
rst <- brick("HYP_50M_SR_W/HYP_50M_SR_W.tif")
plotRGB(rst)
tm_shape(rst) + tm_rgb()
#> Raster object has 58320000 (5400 by 10800) cells, which is larger than 1e+07, the maximum size determined by the option max.raster. Therefore, the raster will be shown at a decreased resolution of 1e+07 cells. Set tmap_options(max.raster = c(plot = 58320000, view = 58320000)) to show the whole raster.
#> Linking to GEOS 3.6.1, GDAL 2.2.3, PROJ 4.9.3
由 reprex包 (v0.2.1) 创建于2019年01月30日
devtools::session_info()
#> - Session info ----------------------------------------------------------
#> setting value
#> version R version 3.5.1 (2018-07-02)
#> os Windows 7 x64 SP 1
#> system x86_64, mingw32
#> ui RTerm
#> language (EN)
#> collate English_United States.1252
#> ctype English_United States.1252
#> tz Europe/Berlin
#> date 2019-01-30
#>
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