gs_polygon: Create a polygon 'geom'
In geometr: Generate and Modify Interoperable Geometric Shapes

Description Usage Arguments Details Value Functions See Also Examples

Create any (regular) polygon geometry (of class geom) either by specifying anchor values or by sketching it.

gs_polygon(
  anchor = NULL,
  window = NULL,
  features = 1,
  vertices = 3,
  regular = FALSE,
  ...
)

gs_triangle(anchor = NULL, window = NULL, features = 1, ...)

gs_square(anchor = NULL, window = NULL, features = 1, ...)

gs_rectangle(anchor = NULL, window = NULL, features = 1, ...)

gs_hexagon(anchor = NULL, window = NULL, features = 1, ...)

`anchor`	[`geom(1)`\|`data.frame(1)`] Object to derive the `geom` from. It must include column names `x`, `y` and optionally a custom `fid`.
`window`	[`data.frame(1)`] in case the reference window deviates from the bounding box of `anchor` (minimum and maximum values), specify this here.
`features`	[`integerish(1)`] number of polygons to create.
`vertices`	[`integerish(.)`] number of vertices per polygon; will be recycled if it does not have as many elements as specified in `features`.
`regular`	[`logical(1)`] should the polygon be regular, i.e. point symmetric (`TRUE`) or should the vertices be selected as provided by `anchor` (`FALSE`, default)?
`...`	[various] graphical parameters to `gt_locate`, in case points are sketched; see `gpar`

The argument anchor indicates how the geom is created:

if anchor is set, the geom is created parametrically from the points given in anchor,
if it is not set either window or a default window between 0 and 1 is opened to sketch the geom.

The argument regular determines how the vertices provided in anchor or via template are transformed into a polygon:

if regular = FALSE the resulting polygon is created from all vertices in anchor,
if regular = TRUE, only the first two vertices are considered, as center and indicating the distance to the (outer) radius.

A geom.

gs_triangle: wrapper of gs_polygon where vertices = 3 and regular = TRUE.
gs_square: wrapper of gs_polygon where vertices = 4 and regular = TRUE.
gs_rectangle: wrapper of gs_polygon where vertices = 2, regular = FALSE and the two complementing corners are derived from the two given opposing corners.
gs_hexagon: wrapper of gs_polygon where vertices = 6 and regular = TRUE.

Other geometry shapes: gs_line(), gs_point(), gs_random()

# 1. create a polygon programmatically
coords <- data.frame(x = c(0, 40, 40, 0),
                     y = c(0, 0, 40, 40))

# if no window is set, the bounding box will be set as window
aGeom <- gs_polygon(anchor = coords)
visualise(aGeom)

# derive a regular polygon from the coordinates
aPolygon <- gs_polygon(anchor = coords, vertices = 6, regular = TRUE)
visualise(aPolygon, linecol = "green")
visualise(aGeom, new = FALSE)

# the vertices are plottet relative to the window
window <- data.frame(x = c(-50, 50),
                     y = c(-50, 50))
aPolygon <- setWindow(x = aPolygon, to = window)
visualise(aPolygon, fillcol = "deeppink")

# using a geom as anchor retains its properties (such as the window)
aRectangle <- gs_rectangle(anchor = aPolygon)
visualise(aRectangle, new = FALSE)

# 2. sketch a hexagon
if(dev.interactive()){
  aHexagon <- gs_hexagon(features = 1)
  visualise(aHexagon, linecol = "deeppink", linetype = 2, new = FALSE)
}