MESH2D - Automatic Mesh Generation: quality(p,t) - File Exchange

Code covered by the BSD License

Highlights from
MESH2D - Automatic Mesh Generation

checkgeometry(node,edge,face,... CHECKGEOMETRY: Check a geometry input for MESH2D.
circumcircle(p,t) CIRCUMCIRCLE: XY centre co-ordinates and radius of triangle
connectivity(p,t) CONNECTIVITY: Assemble connectivity data for a triangular mesh.
dist2poly(p,edgexy,lim) Find the minimum distance from the points in P to the polygon defined by
facedemo(n) FACETEST: Example polygonal geometries for MESHFACES.
findedge(p,node,edge,TOL) FINDEDGE: Locate points on edges.
fixmesh(p,t,pfun,tfun) FIXMESH: Ensure that triangular mesh data is consistent.
inpoly(p, node, edge, reltol) INPOLY: Point-in-polygon testing.
mesh2d(node,edge,hdata,option... MESH2D: 2D unstructured mesh generation for a polygon.
mesh_collection(num) MESH_COLLECTION: Collection of meshing examples from MESH2D users.
meshdemo Demo function for mesh2d.
meshfaces(node,edge,face,hdat... MESHFACES: 2D unstructured mesh generation for polygonal geometry.
meshpoly(node,edge,qtree,p,op... MESHPOLY: Core meshing routine called by mesh2d and meshfaces.
mydelaunayn(p) My version of the MATLAB delaunayn function that attempts to deal with
mytsearch(x,y,t,xi,yi,i) MYTSEARCH: Find the enclosing triangle for points in a 2D plane.
quadtree(node,edge,hdata,dhma... QUADTREE: 2D quadtree decomposition of polygonal geometry.
quality(p,t) QUALITY: Approximate triangle quality.
refine(p,t,ti,f) REFINE: Refine triangular meshes.
smoothmesh(p,t,maxit,tol) SMOOTHMESH: Smooth a triangular mesh using Laplacian smoothing.
tinterp(p,t,f,pi,i) TINTERP: Triangle based linear interpolation.
triarea(p,t) TRIAREA: Area of triangles assuming counter-clockwise (CCW) node
View all files

from MESH2D - Automatic Mesh Generation by Darren Engwirda
Generates unstructured triangular meshes for general 2D geometry.

quality(p,t)

function q = quality(p,t)

%  QUALITY: Approximate triangle quality. 
%
%  q = quality(p,t);
%
%  p: Nx2 array of nodal XY coordinates, [x1,y1; x2,y2; etc]
%  t: Mx3 array of triangles as indices, [n11,n12,n13; n21,n22,n23; etc]
%  q: Mx1 vector of triangle qualities. 0<=q<=1.

% Darren Engwirda - 2007.

% Nodes
p1 = p(t(:,1),:); 
p2 = p(t(:,2),:); 
p3 = p(t(:,3),:);

% Approximate quality
d12 = p2-p1;
d13 = p3-p1;
d23 = p3-p2;
q = 3.4641*abs(d12(:,1).*d13(:,2)-d12(:,2).*d13(:,1))./sum(d12.^2+d13.^2+d23.^2,2);

end      % quality()

Highlights from MESH2D - Automatic Mesh Generation

Highlights from
MESH2D - Automatic Mesh Generation