# centroid.owin

0th

Percentile

##### Centroid of a window

Computes the centroid (centre of mass) of a window

Keywords
spatial, math
##### Usage
centroid.owin(w)
w
A window
##### Details

The centroid of the window w is computed. The centroid (centre of mass'') is the point whose $x$ and $y$ coordinates are the mean values of the $x$ and $y$ coordinates of all points in the window.

The argument w should be a window (an object of class "owin", see owin.object for details) or can be given in any format acceptable to as.owin().

The calculation uses an exact analytic formula for the case of polygonal windows.

Note that the centroid of a window is not necessarily inside the window. If the window is convex then it does contain its centroid.

##### Value

• A list with components x, y giving the coordinates of the centroid of the window w.

owin, as.owin

##### Aliases
• centroid.owin
##### Examples
w <- owin(c(0,1),c(0,1))
centroid.owin(w)
# returns 0.5, 0.5

data(demopat)
w <- demopat\$window
# an irregular window
plot(w)
# plot the window
points(centroid.owin(w))
# mark its centroid

centroid.owin(wapprox)</testonly>