Legend transparency for raster plots not working in version 4.0

[gilbertocamara]

Hi @mtennekes I am migrating my code to tmap version 4.0 and notice that the legend transparency is not working. Here's a MWE.

# get one file for plotting
modis_file <- "https://www.dropbox.com/scl/fi/ykgw4envpvmlgcqee93gb/TERRA_MODIS_012010_NDVI_2013-09-14.jp2?rlkey=3tmm8w9u8m0mvnylrtddgh1k2&dl=1"

# read raster data as a stars object
st <- stars::read_stars(modis_file, along = "band", proxy = FALSE)
# scale the data
st <- st * 0.0001

p1 <- tmap::tm_shape(st, raster.downsample = FALSE) +
    tmap::tm_raster(
        col.scale = tm_scale_continuous(
                                       values = "brewer.rd_yl_gn",
                                        midpoint = NA),
        col.legend = tm_legend(
            title = "NDVI",
            position = tm_pos_in("left", "bottom"),
            frame = TRUE,
            bg.color = "white",
            bg.alpha = 0.8
        )
    ) +
    tmap::tm_graticules(labels.size = 0.7) +
    tmap::tm_compass() 

In the above code, the value of bg.alpha makes no difference in the output.

Allow me to congratulate you for the excellent work on tmap. Please also allow me a futher question. In version 3.3, the scale parameter allowed general control over the plot output. What is the equivalent of scale in version 4.0?

[olivroy]

@mtennekes as preventive action, you can also take a look at https://github.com/r-devel/recheck and follow the step to run the action.

[mtennekes]

@gilbertocamara thanks for your input! bg.alpha should be working now.
The scale parameter is working the same, e.g. ... + tm_layout(scale = 0.8). Somehow, it didn't work well with the legend, but now it does. Please check.

[mtennekes]

@mtennekes as preventive action, you can also take a look at https://github.com/r-devel/recheck and follow the step to run the action.

Thx for the tip. I am aware of these and similar automatic checks. We could do that later on.