[FORGED] circular spatial polygon
This is also possible with rgeos
library(sp)
library(rgeos)
x <- 673593.21
y <- 673593.21
sp0 <- SpatialPoints(coords = data.frame(x=x, y=y),
proj4string = CRS('+proj=utm +zone=20 +south
+ellps=WGS84 +datum=WGS84 +units=m +no_defs'))
sp1 <- gBuffer(sp0, byid=TRUE, width = 15, quadsegs = 2)
plot(sp1)
Cheers,
Lo?c
On 12/09/2017 16:57, Rolf Turner wrote:
On 13/09/17 08:48, K?tia Emidio wrote:
Dear all, My question is how to create a circular spatial polygon, with 8 arcs of 45 degrees, and radius measuring 15m. Having in the centre point the UTM coordinates, zone 20S. x= *673593.21* y= *673593.21*
"Circular polygon" is a contradiction in terms. If a shape is a polygon
then it is *not* a circle. (Of course in real life we use polygons with
large numbers of sides to *approximate* circles. But 8 is not large!)
You can create an octagon with the required centre and radius using
*spatstat* via:
oct <- disc(radius=15,centre=c(673593.21,673593.21),npoly=8)
Does that provide (at least a start on) what you want?
cheers,
Rolf Turner