Rank: 194 based on 502 downloads (last 30 days) and 6 files submitted
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Files Posted by Darren View all
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(last 30 days)
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12 Oct 2009 Screenshot MESH2D - Automatic Mesh Generation Generates unstructured triangular meshes for general 2D geometry. Author: Darren Engwirda mathematics, simulation, modeling, fem, fvm, mesh generation 249 34
  • 5.0
5.0 | 18 ratings
03 Dec 2007 Screenshot Fast points-in-polygon test Fast test to determine points located inside general polygon regions. Should be significantly faster Author: Darren Engwirda points inside polygon, image processing, inpolygon, polygon 90 20
  • 4.375
4.4 | 17 ratings
30 Nov 2006 Screenshot tinterp - an alternative to griddata Linear and quadratic interpolation for scattered data Author: Darren Engwirda approximation, interpolation, scattered interpolati..., linear, quadratic, 2d 38 4
  • 5.0
5.0 | 3 ratings
15 May 2006 Screenshot Contours for triangular grids Generate smooth contours for functions defined on unstructured triangular grids Author: Darren Engwirda specialized, plotting, unstructured, mesh, contours, graphics 96 16
  • 5.0
5.0 | 16 ratings
03 Apr 2006 Fast sparse matrix vector product sparse matrix vector product Author: Darren Engwirda linear algebra, sparse, matrix, vector, product 19 7
  • 3.8
3.8 | 5 ratings
Comments and Ratings by Darren View all
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09 Aug 2011 MESH2D - Automatic Mesh Generation Generates unstructured triangular meshes for general 2D geometry. Author: Darren Engwirda

Hi Philippe, you may want to have a look at the utility "connectivity" routine. Amongst other things, it will identify the boundary nodes in a mesh.

14 Oct 2009 MESH2D - Automatic Mesh Generation Generates unstructured triangular meshes for general 2D geometry. Author: Darren Engwirda

Author comment: v24 was posted to resolve a licence conflict. The Mathworks no longer allows code to be released under a GNU GPL, so this has been removed for v24.

There are some (minor) revisions to the code, based on user feedback. Specifically, v24 may be slightly slower than v23, but should generally produce higher quality meshes, especially for complex geometries.

Comments/feedback is always welcome - d_engwirda@hotmail.com

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10 Apr 2014 MESH2D - Automatic Mesh Generation Generates unstructured triangular meshes for general 2D geometry. Author: Darren Engwirda Benson, Thomas

This is a great submission! A minor change was required for my application. Reason: The triangulation tends to be slightly over-refined on complex boundaries. For some applications this is a bonus, but for hydrodymanic modelling it is not really necessary. I therefore replaced the line in 'quadtree.m' (about line 64) which reads:

L = 2.0*dist2poly(wm,edgexy,2.0*len);

with the following:

L=len;

This helps prevent over refinement and a nice mesh. Excellent work Darren!

26 Feb 2014 MESH2D - Automatic Mesh Generation Generates unstructured triangular meshes for general 2D geometry. Author: Darren Engwirda Abdulrahman

03 Feb 2014 MESH2D - Automatic Mesh Generation Generates unstructured triangular meshes for general 2D geometry. Author: Darren Engwirda Abdulrahman

Great work thank you very much.

I've got a question I appreciate if any one could help, where exactly the changes can take place ? I know it would be most about the geometry but I wasn't able to play with it.

19 Dec 2013 MESH2D - Automatic Mesh Generation Generates unstructured triangular meshes for general 2D geometry. Author: Darren Engwirda Marcus

I'm doing something that must be pretty standard. I'm needing to mesh a 2d domain with an internal boundary. My approach has been to create 'holes' with zero area, which imposes duplicate nodes. Mesh2d seems able to remove these and gives e.g., the message 'WARNING: 2 duplicate node(s) removed'. However, with some of my examples I get the message: 'Warning: Duplicate data points have been detected. Some data points do not map to vertices in the triangulation. To avoid this behavior, call UNIQUE on the data points prior to calling DELAUNAY.' Now what I would like to know is whether this problem in the geometry is fixed by Mesh2d? I include a simple example of the sort of problem I'm interested in.
PS. Mesh2d has proved invaluable - Thank you!
***********************************
p1 = [0 0; ...
3 0; ...
3 3; ...
0 3];
p2 = [0.5 1.5; ...
1.5 1.5; ...
1.5 2.5; ...
1.5 1.5; ...
0.5 1.5];
n1 = size(p1,1);
n2 = size(p2,1);
c1 = [(1:n1-1)', (2:n1)'; n1, 1];
c2 = [(1:n2-1)', (2:n2)'; n2, 1];
node = [p1; p2];
cnect = [c1;c2+n1];
hdata.hmax = 1;
[p,t] = mesh2d(node,cnect,hdata,[]);
*****************************************

22 Oct 2013 MESH2D - Automatic Mesh Generation Generates unstructured triangular meshes for general 2D geometry. Author: Darren Engwirda Clarke, Richard

Great routine, although I was having some issues removing redundant nodes until I changed the following in line 66 of changegeometry.m

del = nNode-i(end);

-->

del = nNode-length(i);

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