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Thread: Concave hull algorithm in Delphi?


This question is not answered. Helpful answers available: 2. Correct answers available: 1.


Permlink Replies: 10 - Last Post: Feb 27, 2018 1:02 AM Last Post By: Peter Stadler
Peter Stadler

Posts: 9
Registered: 11/5/05
Concave hull algorithm in Delphi?  
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  Posted: Jul 8, 2017 1:33 AM
Hello,
I am searching a delphi translation of a Concave hull algorithm. It was developed by a portuguese institute here in Mathematica.
http://repositorium.sdum.uminho.pt/bitstream/1822/6429/1/ConcaveHull_ACM_MYS.pdf

Later it was translated into C#.

Has anybody made a translation to delphi?

Sincerely

Peter
Rudy Velthuis (...


Posts: 7,731
Registered: 9/22/99
Re: Concave hull algorithm in Delphi?  
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  Posted: Jul 8, 2017 2:05 AM   in response to: Peter Stadler in response to: Peter Stadler
Peter Stadler wrote:

Hello,
I am searching a delphi translation of a Concave hull algorithm. It
was developed by a portuguese institute here in Mathematica.
http://repositorium.sdum.uminho.pt/bitstream/1822/6429/1/ConcaveHull_ACM_MYS.pdf

Later it was translated into C#.

Has anybody made a translation to delphi?

If not, you'll either have to translate the original Mathematica or the
C# version. I would try to convert the C# version first, although the
Mathematica one doesn't look too complicated.

--
Rudy Velthuis http://www.rvelthuis.de

"Never test for an error condition you don't know how to handle."
-- Steinbach's Guideline for Systems Programmers.
Rudy Velthuis (...


Posts: 7,731
Registered: 9/22/99
Re: Concave hull algorithm in Delphi?  
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  Posted: Jul 8, 2017 2:22 AM   in response to: Rudy Velthuis (... in response to: Rudy Velthuis (...
Rudy Velthuis (TeamB, MVP) wrote:

Peter Stadler wrote:

Hello,
I am searching a delphi translation of a Concave hull algorithm. It
was developed by a portuguese institute here in Mathematica.
http://repositorium.sdum.uminho.pt/bitstream/1822/6429/1/ConcaveHull_ACM_MYS.pdf

Later it was translated into C#.

Has anybody made a translation to delphi?

If not, you'll either have to translate the original Mathematica or
the C# version. I would try to convert the C# version first, although
the Mathematica one doesn't look too complicated.

But it might require you to write some extra functions, like
CleanList(), FindMinYPoint() etc. Should be doable. CleanList is
easiest if you sort it first.

--
Rudy Velthuis http://www.rvelthuis.de

"I'm not a member of any organized political party, I'm a
Democrat!" -- Will Rogers (1879-1935)
Peter Stadler

Posts: 9
Registered: 11/5/05
Re: Concave hull algorithm in Delphi?  
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  Posted: Jul 9, 2017 12:45 AM   in response to: Peter Stadler in response to: Peter Stadler
Hello,

Thank you Rudy Velthuis to your contribution.

I found the most recent implementation http://andriiheonia.github.io/hull/.

It is written in javascript.

So my question still is: Has anybody translated it to delphi?

I would also pay for a translation. There are only in total 358 lines of source code.

Sincerely

Peter
Rudy Velthuis (...


Posts: 7,731
Registered: 9/22/99
Re: Concave hull algorithm in Delphi?  
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  Posted: Jul 9, 2017 1:27 AM   in response to: Peter Stadler in response to: Peter Stadler
Peter Stadler wrote:

Hello,

Thank you Rudy Velthuis to your contribution.

I found the most recent implementation
http://andriiheonia.github.io/hull/.

It is written in javascript.

So my question still is: Has anybody translated it to delphi?

I would also pay for a translation. There are only in total 358 lines
of source code.

Sincerely

Peter

Do you have a link to the C# translation? And is that a translation, or
just different convex hull code?

--
Rudy Velthuis http://www.rvelthuis.de

"Real Programmers always confuse Christmas and Halloween because
Oct31 == Dec25 !" -- Andrew Rutherford
Shlomo Abuisak

Posts: 100
Registered: 9/18/10
Re: Concave hull algorithm in Delphi?  
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  Posted: Jul 9, 2017 11:29 AM   in response to: Peter Stadler in response to: Peter Stadler
On 09/07/2017 10:45, Peter Stadler wrote:
Hello,

Thank you Rudy Velthuis to your contribution.

I found the most recent implementation http://andriiheonia.github.io/hull/.

It is written in javascript.

So my question still is: Has anybody translated it to delphi?

I would also pay for a translation. There are only in total 358 lines of source code.

Sincerely

Peter
can this help ?
http://www.delphiforfun.org/Programs/Fences.htm
Peter Stadler

Posts: 9
Registered: 11/5/05
Re: Concave hull algorithm in Delphi?  
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  Posted: Jul 9, 2017 6:21 AM   in response to: Peter Stadler in response to: Peter Stadler
Hello Rudy,

The C# code is not the best. Much better is the code with link mentioned in my last post.

Peter
Rudy Velthuis (...


Posts: 7,731
Registered: 9/22/99
Re: Concave hull algorithm in Delphi?  
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  Posted: Jul 9, 2017 6:25 AM   in response to: Peter Stadler in response to: Peter Stadler
Peter Stadler wrote:

Hello Rudy,

The C# code is not the best. Much better is the code with link
mentioned in my last post.

But C# is much easier to translate. <g>


--
Rudy Velthuis http://www.rvelthuis.de

"Someday man will imprison the power of the sun, release atomic
power, and harness the rise and fall of the tides. I am proud
of the fact that I never invented weapons to kill."
-- Thomas Edison

Peter Stadler

Posts: 9
Registered: 11/5/05
Re: Concave hull algorithm in Delphi?  
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  Posted: Jul 9, 2017 10:18 AM   in response to: Peter Stadler in response to: Peter Stadler
Hello Rudy,

The c# was from a discussion forum, where somebody talked about how to make the translation from Mathematica.

Andrii has produced from the original publication a much extended and further developed version as you can see in his graphs presented here:

http://andriiheonia.github.io/hull/

The source code with Javascript can be found here:

https://github.com/AndriiHeonia/hull

For me javascript and c# are both difficult to understand from point of view with delphi!

Sincerely Peter
Peter Stadler

Posts: 9
Registered: 11/5/05
Re: Concave hull algorithm in Delphi?  
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  Posted: Jul 9, 2017 12:49 PM   in response to: Peter Stadler in response to: Peter Stadler
Thank you,

I already know this page. But it is about convex hull, not concave hull.

Sincerely

Peter
Peter Stadler

Posts: 9
Registered: 11/5/05
Re: Concave hull algorithm in Delphi?  
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  Posted: Feb 27, 2018 1:02 AM   in response to: Peter Stadler in response to: Peter Stadler
Hello,

I found now an implementation of the concave hull in c++.
https://www.codeproject.com/Articles/1201438/The-Concave-Hull-of-a-Set-of-Points

It uses also the Flann library.

Has anybody installed it in Embarcadero C++Builder?

Sincerely Peter
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