geom_sf alpha not working for linestring #311
Description
I expected alpha to work for linestring sf object as in geom_line. Here is a simple example:
library(ggplot2)
library(sf)
l <- st_linestring(rbind(c(2,2), c(3,3), c(3,2)))
lsf <- st_sf(geometry = st_sfc(l, crs = 4326))
ggplot(data = lsf) + geom_sf(data = lsf, lwd = 2)
ggplot(data = lsf) + geom_sf(data = lsf, alpha = 0.5, lwd = 2)
both plots above are identical.
If I try with polygon, fill transparency changes but outline remains the same.
p <- st_polygon(list(rbind(c(2,2), c(3,3), c(3,2), c(2,2))))
psf <- st_sf(geometry = st_sfc(p, crs = 4326))
ggplot(data = psf) + geom_sf(data = psf)
ggplot(data = psf) + geom_sf(data = psf, alpha = 0.5)
Using geom_line, it works:
lpt <- st_coordinates(lsf) %>% tbl_df()
ggplot() + geom_line(data = lpt, aes(x = X, y = Y), alpha = 0.2)