Add buffer polygons of varying shapes and widths around points in sf object

[HABSaremyjam]

Hello,

I would like to create polygons around points in an sf object whose size and shape is dependent upon the "Size" and "Shape" columns and plot them using ggplot2. Essentially I want to create a buffer around these points.

library(sf)

data <- structure(list(Year = c(1995L, 2009L, 2012L, 2016L, 2017L), Latitude = c(46.966275, 
47.218215, 46.883583, 46.903478, 46.8763623), Longitude = c(-90.901083, 
-91.350019, -91.04902, -91.032777, -91.1884869), Size = c(5, 
50, 100, 1000, 200), Shape = c("Circle", "Square", "Line", "Line", 
"Circle")), row.names = c(NA, 5L), class = "data.frame")

sf <- st_as_sf(data, coords = c("Longitude", "Latitude"), crs = 4326)

For example, for the year 2016, I would like a buffer around this point that is very long (1000 m) but not very wide (maybe 2-5 m long), but for the year 2017, I would like a circle that is 200 m in diameter.

I tried using st_buffer() but it doesn't give options for shape. I also looked into st_convex_hull but didn't see any customization options.

Does anyone have any idea how to achieve what I'm trying to achieve?

Thanks so much for any help you can provide!

[williaml]

Hi, buffers are equidistant from the spatial feature. You can't define the shape (not that I know of anyway).