AlphaShapes.AlphaShape
— MethodAlphaShape(X::AbstractArray{Float64,2};α::Union{Nothing,Float64}=nothing,
search::Tuple{Float64,Float64}=(0.0, 10.0),
MaxSteps::Int=100)::AbstractArray{Float64,3}
Find the alpha shape corresponding to the 2D AbstractArray of points X: [2,npoints], and the α value α.
If α == nothing then a search over the range of values search is done to find the best value. The optimisation objective is the alpha shape area (minimise) subject to all points in X being included in the alpha shape triangulation.
AlphaShapes.AlphaShapeVolume
— MethodAlphaShapeVolume(A::AbstractArray{Float64,3})
return the sum of volumes of all simplices in the alpha shapes A
AlphaShapes.CayleyMenger
— Method CayleyMenger
Compute the Cayley-Menger matrix from squared
distances dij^2.
https://mathworld.wolfram.com/Cayley-MengerDeterminant.html
For a 2-d triangle the following example would symbolically
represent the matrix for points x1, x2, and x3 where dij^2
is the square Euclidean distance between i and j
Example
julia>:([0 1 1 1
1 0 d12^2 d13^2
1 d21^2 0 d23^2
1 d32^2 d32^2 0])
:([0 1 1 1; 1 0 d12 ^ 2 d13 ^ 2; 1 d21 ^ 2 0 d23 ^ 2; 1 d32 ^ 2 d32 ^ 2 0])
AlphaShapes.FindAlpha
— MethodFindAlpha(X::AbstractArray{Float64,2};
search::Tuple{Float64,Float64}=(0.0, 10.0),
MaxSteps::Int=100)::Float64
Use BlackBocOptim to find the optimal alpha value (volume minimiser which cotains all points from the input).
AlphaShapes.GetDelaunayTriangulation
— MethodGetDelaunayTriangulation(points::AbstractArray{Float64,2})::AbstractArray{Float64,3}
Wrap MiniQhull.jl's delaunay to get a delaunay triangualation in any dimension
AlphaShapes.SimplexCircumRadiusSquared
— MethodSimplexCircumSphere
Find the centre and radius of the circumsphere of a simplex https://westy31.home.xs4all.nl/Circumsphere/ncircumsphere.htm
AlphaShapes.SimplexCircumSphere
— MethodSimplexCircumSphere
Find the centre and radius of the circumsphere of a simplex https://westy31.home.xs4all.nl/Circumsphere/ncircumsphere.htm
AlphaShapes.SimplexVolume
— MethodSimplexVolume
Calculate the volume of a simplex using the Cayley Menger matrix
https://westy31.home.xs4all.nl/Circumsphere/ncircumsphere.htm