leaflet.opacity extends the leaflet R package with the Leaflet.OpacityControls JavaScript plugin (LizardTech, 2013). It offers control buttons and a slider for adjusting the opacity of a layer.
You can install the released version of leaflet.opacity from CRAN with:
install.packages("leaflet.opacity")
or the latest version from GitHub with:
devtools::install_github("https://github.com/be-marc/leaflet.opacity", dependencies=TRUE)
library(leaflet)
library(leaflet.opacity)
library(raster)
r <- raster(xmn = -2.8, xmx = -2.79, ymn = 54.04, ymx = 54.05, nrows = 30, ncols = 30)
values(r) <- matrix(1:900, nrow(r), ncol(r), byrow = TRUE)
crs(r) <- CRS("+init=epsg:4326")
leaflet() %>%
addTiles() %>%
addRasterImage(r, layerId = "raster") %>%
addOpacitySlider(layerId = "raster")
LizardTech (2013). Leaflet.OpacityControls. Retrieved from https://github.com/lizardtechblog/Leaflet.OpacityControls