is.convex

0th

Percentile

Test Whether a Window is Convex

Determines whether a window is convex.

Keywords
manip, spatial
Usage
is.convex(x)
Arguments
x
Window (object of class "owin").
Details

If x is a rectangle, the result is TRUE.

If x is polygonal, the result is TRUE if x consists of a single polygon and this polygon is equal to the minimal convex hull of its vertices computed by chull.

If x is a mask, the algorithm first extracts all boundary pixels of x using vertices. Then it computes the (polygonal) convex hull $K$ of the boundary pixels. The result is TRUE if every boundary pixel lies within one pixel diameter of an edge of $K$.

Value

• Logical value, equal to TRUE if x is convex.

owin, convexhull.xy, vertices