Calculates and returns an overlay of points for the current map.
generate_point_overlay(
geometry,
extent,
heightmap = NULL,
width = NA,
height = NA,
resolution_multiply = 1,
pch = 20,
color = "black",
size = 1,
offset = c(0, 0),
data_column_width = NULL
)Arguments
- geometry
An `sf` object with POINT geometry.
- extent
Either an object representing the spatial extent of the scene (either from the `raster`, `terra`, `sf`, or `sp` packages), a length-4 numeric vector specifying `c("xmin", "xmax","ymin","ymax")`, or the spatial object (from the previously aforementioned packages) which will be automatically converted to an extent object.
- heightmap
Default `NULL`. The original height map. Pass this in to extract the dimensions of the resulting overlay automatically.
- width
Default `NA`. Width of the resulting overlay. Default the same dimensions as height map.
- height
Default `NA`. Width of the resulting overlay. Default the same dimensions as height map.
- resolution_multiply
Default `1`. If passing in `heightmap` instead of width/height, amount to increase the resolution of the overlay, which should make lines/polygons/points finer. Should be combined with `add_overlay(rescale_original = TRUE)` to ensure those added details are captured in the final map.
- pch
Default `20`, solid. Point symbol. `0` = square, `1` = circle, `2` = triangle point up, `3` = plus, `4` = cross, `5` = diamond, `6` = triangle point down, `7` = square cross, `8` = star, `9` = diamond plus, `10` = circle plus, `11` = triangles up and down, `12` = square plus, `13` = circle cross, `14` = square and triangle down, `15` = filled square, `16` = filled circle, `17` = filled triangle point-up, `18` = filled diamond, `19` = solid circle, `20` = bullet (smaller circle), `21` = filled circle blue, `22` = filled square blue, `23` = filled diamond blue, `24` = filled triangle point-up blue, `25` = filled triangle point down blue
- color
Default `black`. Color of the points.
- size
Default `1`. Point size.
- offset
Default `c(0,0)`. Horizontal and vertical offset to apply to the polygon, in units of `geometry`.
- data_column_width
Default `NULL`. The numeric column to map the width to. The maximum width will be the value specified in `linewidth`.
Value
Semi-transparent overlay with contours.
Examples
#Add the included `sf` object with roads to the montereybay dataset
if(run_documentation()) {
monterey_city = sf::st_sfc(sf::st_point(c(-121.893611, 36.603056)))
montereybay %>%
height_shade() %>%
add_overlay(generate_point_overlay(monterey_city, color="red", size=12,
attr(montereybay,"extent"), heightmap = montereybay)) %>%
add_shadow(ray_shade(montereybay,zscale=50),0.3) %>%
plot_map()
}
