# Integral evaluation in an alphashape

2 views (last 30 days)
berk can acikgoz on 11 Mar 2020
Edited: Matt J on 12 Mar 2020
I have an alphashape created by alphaShape function and an integral. Is there a way to evaluate this volume integral in the alpha shape? i.e. I have a function and I want to find the volume integral of this function in the shape defined by
x coordinates:
0
0.0107
0.0160
0.0101
y coordinates:
0
0
0
0.0106
z coordinates:
0
0.0101
0
0

darova on 11 Mar 2020
I plotted the sphere and points. Looks as following: You want to calculate the volume numerically?
I found some links for area calculation: wolfram
berk can acikgoz on 12 Mar 2020
It is actually a volume integral. Also it is a tetrahedral. I know how to integrate 3D but i dont want to since there are too many of these tetrahedrals and each time i will have to calculate the integration boundaries etc.
darova on 12 Mar 2020    Matt J on 11 Mar 2020
Edited: Matt J on 11 Mar 2020
Perhaps as follows. Here, shp refers to your alphaShape object.
fun=@(x,y,z) (x.^2+y.^2+z.^2).*shp.inShape(x,y,z);
range=num2cell( [min(shp.Points);max(shp.Points)] );
result=integral3(fun,range{:});