This is machine translation

Translated by Microsoft
Mouseover text to see original. Click the button below to return to the English verison of the page.

Note: This page has been translated by MathWorks. Please click here
To view all translated materals including this page, select Japan from the country navigator on the bottom of this page.


Class: triangulation

Incenter of triangle or tetrahedron


IC = incenter(TR,ti)
[IC,r] = incenter(TR,ti)


IC = incenter(TR,ti) returns the coordinates of the incenter of each triangle or tetrahedron specified by ti.

[IC,r] = incenter(TR,ti) also returns the radii of the inscribed circles or spheres.

Input Arguments


Triangulation representation, see triangulation or delaunayTriangulation.


Triangle or tetrahedron IDs, specified as a column vector.

Output Arguments


Incenters, returned as a matrix. Each row of IC contains the coordinates of an incenter. For example, IC(j,:) is the incenter of ti(j).


Radii of the inscribed circles or spheres, returned as a vector. r(j) is the radius of the inscribed circle or sphere whose center is IC(j,:).


Triangle or Tetrahedron ID

A row number of the matrix, TR.ConnectivityList. Use this ID to refer a specific triangle or tetrahedron.


expand all

Load a 3-D triangulation.

load tetmesh

Calculate the incenters of the first five tetrahedra.

TR = triangulation(tet,X);
IC = incenter(TR,[1:5]')
IC =

   -6.1083  -31.0234    8.1439
   -2.1439  -31.0283    5.8742
   -1.9555  -31.9463    7.4112
   -4.3019  -30.8460   10.5169
   -3.1596  -29.3642    6.1851

Create the Delaunay triangulation.

x = [0 1 1 0 0.5]';
y = [0 0 1 1 0.5]';
DT = delaunayTriangulation(x,y);

Calculate incenters of the triangles

IC = incenter(DT)
IC =

    0.2071    0.5000
    0.5000    0.7929
    0.7929    0.5000
    0.5000    0.2071

Plot the triangles and incenters.

axis equal
axis([-0.2 1.2 -0.2 1.2])
hold on
hold off

Was this topic helpful?