Archive for the ‘Matlab’ Category

After the Mathworks staff refusal of activating html contents on Matlab exchange I finally take the ultimate decision: Operation Exodus.

All my tools description will be  moved from file exchange  to:

www.advancedmcode.org

Each products will have its own webpage (with many, but many never enough, html contents) , it will be possibile to rate them  (without filtering).

From  now  on, almost each I will update one of my product on a “free website”. I suggest you to join my cause, you will have your personal donation button and the liberty to edit your page as you desire.

Over

Are you interested in blogging?

I am starting a new project trying to involve all possible Matlab users. I am thinging about a blog where everybody can place a post/program/question.

It is not fully operative yet, but it will be soon:

http://www.advancedmcode.org/

This something new so if you have anything in mind just let me know,

Feedback is greatly appriecieted

I publish this post hoping to give an answer to the more common questions I receive on my e-mail.

The first thing we’ve got to see in our points cloud is that the resulting surface is in the z=f(x,y) form. If yes, than the solution is easier than it seems, we just have to triangulate x and y coordinates, for example using delaunay, and after that plot all trhee coordinates. Notice that if points are structured (diposed on a grid) there is no need to use delaunay to build a triangular mesh that’s enough a for loop. An implementation of a structured grid genration can be found at:

http://www.mathworks.com/matlabcentral/fileexchange/23916

A complete  example on how to plot the surface can be downloaded at:

http://www.mathworks.com/matlabcentral/fileexchange/23447

It also shown how to colour the final surface with assingned rgb triplets at each points.

If the surface is not in the z=f(x,y) form, things get a little more complicated. Now we have to check if the surface is in convex, if yes we can smile. All we have to do now is to tessellate the 3D points with the convhulln function and then simply use the trisurf command to plot our surface. Since the final surface is convex, the convhull function ensure a correct tesselation.

And waht if the final surface is not convex. We are entering in the more complicate field of surface recostruction. Now the recostruction is not assured to be correct and the algorithm to choose mainly depends on the kind of dataset we are facing:

• Closed surface: a crust based algorithm will be good, an implementation is on:
  http://www.mathworks.com/matlabcentral/fileexchange/22185
• Open surface:  open surfaces are tricky, sometimes thay are not even orientable. For those the Crust based algotihm fails because it requires a volume that with an open surface can not be defined. An algorithm for open surfaces can be get at:
  http://www.mathworks.com/matlabcentral/fileexchange/22595
• Filled clouds: when we want to get a surface from points generally all the points include in the input will be part of the final surface. But sometimes cloud points are filled, they can contain a lot of internal points that are not supposed to lye on the surface. This kind of dataset requires a ball pivoting algorithm or a ballfretting one that can be found at:
  http://www.mathworks.com/matlabcentral/fileexchange/23447
• Sliced data: Sliced data are somehow easier to treat because, differently from scattered points cloud, here we partially know the points disposition. I’ll be working on one of this algorithm, I will publish a link when it is finished.

It is now available on Matlab file exchange the robust and new version of MyCrust. It can be downloaded at:

I hope you’ll enjoy it !

The old version did not ensure the output surface to be a manifold so it could be used only for graphical purpose. In the new one a tight, regular manifold is returned. It as outward normals orientation, after using this algorithm is very easy to get an STL file from a point cloud.

I added a manifold extraction tool that also correct the errors (slivers) generated by delaunayn during the initial tessellation.

I want to inform you that I intend to design an algorithm for sliced points cloud but I don’t have demos to test my works. If you have some please send them to my e-mail. The tool will be open source and it will be published on Matlab file exchange.

I am also opening a few more section in the website, if you are willing to share some Matlab tutorial, documentation, code don’t hesitate to contact me.

See you guys

New products on File exchange

These days I am upload many of the addictional tools that previuosy marke as product extensions.
I want to underline:

• Poker Predictor:

  allows fast and accurate simulations of texas holdem games.

• GLTREE 3D :

  the 3D version of the one already present on FEX. Alloes for very fast nearest neighbours location.

• Ball fretting algorihm :

  A surfaca recostruction tool, similar to the ball pivoting, designed for filled cloud points.

All tools will be available on my Matlab author’s personal page.

They are all free, if you find it usefull doantions can be made on the PAYPAL link.

Others tools will be updated in future, a normals computation one, a 2D mesher, a surface domains decomposition.

See you on next post.

Two new Products are now avalaible:

1. GLTree3D (MEX VERSION) :
   The speed of the fastest nearest neighobur algorithm in the world with Matlab compatibility as bonus.
   GLTree offers linear  tree time costruction, extraoridary fast neighbourood search and more, not less important, it is up to you to decide the price.
   Test the 2D version freely avalaiable on MATLAB File Exchange.
   Sohuld work on all platform, it requires a mex compiler.
2. Surface Volume:
   I’have seen some posts on the newsreader asking how to compute the Volume of 3D trisngulated surface. Here it is the solution.

For more info refer to Products Extentions Page

I finally got an adsl internet connection, exactly 40 days after I required it.

This video may sounds funny but unfortunatly is terribly true. The worst part is that it shows only the minor part of Italian continups downgrade. You should see our politicians!!, Corruption and ignorance is destroying the “Bel Paese”.    So I want to launch a provocatory announcement to foreign governements:

Please Invade Us !!

You will find negligible opposition.

Hi I am currently without internet connection, I borrow my friend’s UMTS cell phone to get on line once in a day. So I apologize  for my late e-mail feedback.

I just wanted to put into attention the latest products on FEX, you can find all them inthe section products or in the new Poker Room:

• Structered Triangular and tetraedral mesh generation, to get your meshes on rectangular topological shape.
• Surface parametrizer to get a 2D domain from a 3D triagnulated surface.

Most of all I am particullarry proud of the newTexas holdem Poker Odd calcualtor : Poker predictor.

I am Poker player so I had this Idea, to make my game less empirical and more rational.  I tried on field and I can assure you it works good. Discover his functionalities on the Poker room or get the demo version on:

http://www.mathworks.com/matlabcentral/fileexchange/23966

I am alwais opened to suggestions questions so if you have something in mind just contact me.

Hi,

here are proposed a series of works, some of them are almost completed some of them are just ideas. The survey will let me understand which program can be more requested, so I can concentrate more time on it.

I am also opened to ideas, so if you need something just contact me on my e-mail.

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