In R, how to make dots transparent while using scale_size in ggplot2?
ggmap, ggplot2, google-maps, r, visualization
Solution
To use a uniform transparency, just add `alpha = 0.3` to `geom_point`. `alpha` can be between 0 and 1, depending on the amount of transparency you want. If you want to make you transparency depend on a variable, just add `alpha = var_name` to the `mapping` argument (the `aes` bit), where `var_name` is the column name of the variable you want to use for transparency.
Problem
This equation leads from my previous question. I want to plot dots that represent total population and so far I used `scale_size` to make dots' size relative to its total population. But, I want to make these dots transparent because the dots are covering the map. I am, however, open to other options as long as the message I am trying to send is clear. ``` # load required packages library(ggmap) library(ggplot2) # query map of Birmingham, AL al1 <- get_map(location = c(lon = -86.304474, lat = 32.362563), zoom = 11, source = "osm", maptype = 'terrain') al1MAP <- ggmap(al1)+ geom_point(data=quote_bmh, aes(x=IntPtLon, y=IntPtLat, size=TotPop, colour="gold2"), colour="gold2") + scale_size(range=c(0,15)) ```