El día 20 de noviembre de 2011 23:28, Juan Pablo Carbajal
<carba...@ifi.uzh.ch> escribió:
> 2011/11/20 José Luis García Pallero <jgpall...@gmail.com>:
>> 2011/11/20 Juan Pablo Carbajal <carba...@ifi.uzh.ch>:
>>> 2011/11/20 José Luis García Pallero <jgpall...@gmail.com>:
>>>> 2011/11/20 Carnë Draug <carandraug+...@gmail.com>:
>>>>> On 19 November 2011 00:40, Tobias Andersson <xyzto...@hotmail.com> wrote:
>>>>>> First of all, hi everyone! I'm new here and hope that this is the right
>>>>>> way
>>>>>> to post bug reports. Otherwise, please inform me how to do it.
>>>>>> Now, I installed octclip to find intersections between polygons and
>>>>>> found an
>>>>>> odd behaviour when sections of different polygons follow the same line.
>>>>>> Also, Strange results are returned when a section "touches" a point in
>>>>>> the
>>>>>> other polygon.
>>>>>> The problem is that the result in the first example should be one polygon
>>>>>> and that the result in the second example should be a polygon without the
>>>>>> duplicate point [2.4 2.4].
>>>>>> I thank you for updating the package or advising me if I think wrong on
>>>>>> how
>>>>>> the functionality should be.
>>>>>>
>>>>>>
>>>>>> Two example codes are shown below so that you can rerun the script
>>>>>> yourselves:
>>>>>> 1. Sections of different polygons follow the same line:
>>>>>> % This is a script to generate a polygon and plot it in a figure and find
>>>>>> intersection
>>>>>> polygons(1).p = [ 2.2 2.2;
>>>>>> 3.4 3.4;
>>>>>> 6.3 3.4;
>>>>>> 5.3 2.8;
>>>>>> 3.3 2.4];
>>>>>> polygons(2).p = [ 1.2 2.2;
>>>>>> 3.4 3.4;
>>>>>> 5.3 3.4;
>>>>>> 5.3 2.8;
>>>>>> 4.4 2.3;
>>>>>> 3.3 1.7]+5;
>>>>>> polygons(2).p = polygons(2).p + [1*ones(size(polygons(2).p,1),1)
>>>>>> 0*ones(size(polygons(2).p,1),1)];
>>>>>> plot(polygons(1).p(:,1),polygons(1).p(:,2),'*-');
>>>>>> hold on
>>>>>> plot(polygons(1).p([end 1],1),polygons(1).p([end 1],2),'*-');
>>>>>>
>>>>>> plot(polygons(2).p(:,1),polygons(2).p(:,2),'*-.k');
>>>>>> plot(polygons(2).p([end 1],1),polygons(2).p([end 1],2),'*:k');
>>>>>> hold off
>>>>>> [X,Y,nPol,nInt,nPert] = _oc_polybool(polygons(2).p,polygons(1).p,'AND');
>>>>>> fprintf('runPolygonShowNonIntersecting.m\n')
>>>>>> fprintf('Numbers of polygons found: %i\n',nPol)
>>>>>>
>>>>>>
>>>>>> 2. A section "touches" a point in the other polygon:
>>>>>> % This is a script to generate a polygon and plot it in a figure and find
>>>>>> intersection
>>>>>> polygons(1).p = [ 2.2 2.2;
>>>>>> 3.4 3.4;
>>>>>> 6.3 3.4;
>>>>>> 5.3 2.8;
>>>>>> 3.3 2.4];
>>>>>> polygons(2).p = [ 1.2 2.2;
>>>>>> 3.4 3.4;
>>>>>> 5.3 3.4;
>>>>>> 5.3 2.8;
>>>>>> 4.4 2.3;
>>>>>> 3.3 1.7]+0.2;
>>>>>> polygons(2).p = polygons(2).p + [1*ones(size(polygons(2).p,1),1)
>>>>>> 0*ones(size(polygons(2).p,1),1)];
>>>>>> plot(polygons(1).p(:,1),polygons(1).p(:,2),'*-');
>>>>>> hold on
>>>>>> plot(polygons(1).p([end 1],1),polygons(1).p([end 1],2),'*-');
>>>>>>
>>>>>> plot(polygons(2).p(:,1),polygons(2).p(:,2),'*-.k');
>>>>>> plot(polygons(2).p([end 1],1),polygons(2).p([end 1],2),'*:k');
>>>>>> hold off
>>>>>> [X,Y,nPol,nInt,nPert] = _oc_polybool(polygons(2).p,polygons(1).p,'AND');
>>>>>> fprintf('runPolygonShowNonIntersecting.m\n')
>>>>>> fprintf('Numbers of polygons found: %i\n',nPol)
>>>>>
>>>>> Hi Tobias
>>>>>
>>>>> do you think you can submit a patch? Anyway, I'm also sending this
>>>>> e-mail to the dev who wrote this function, he's probably the best
>>>>> person to fix anything about the package.
>>>>>
>>>>> Carnë
>>>>>
>>>>
>>>> Hello,
>>>>
>>>> Tobias, I don't understand when you say that in the first example the
>>>> result should be one polygon. You perform the 'AND' operation but the
>>>> two polygons in your example are disjoints, so they have no
>>>> intersection. The second example runs well for me. Please, see the
>>>> attached *.png files with the results of your examples in my computer
>>>> (in the second one I have added in red the resulting polygon).
>>>>
>>>> Take in account too that I implement the Greiner-Hormann algorithm
>>>> which is not robust when a point or an edge of one polygon coincides
>>>> with a point or an edge of the other. Please, see
>>>> http://davis.wpi.edu/~matt/courses/clipping/ for more details.
>>>>
>>>> About OctCLIP, you should use the oc_polybool function (is a *.m
>>>> script) instead of the _oc_polybool one (is the *.oct function)
>>>>
>>>> Cheers
>>>>
>>>> --
>>>> *****************************************
>>>> José Luis García Pallero
>>>> jgpall...@gmail.com
>>>> (o<
>>>> / / \
>>>> V_/_
>>>> Use Debian GNU/Linux and enjoy!
>>>> *****************************************
>>>>
>>>> ------------------------------------------------------------------------------
>>>> All the data continuously generated in your IT infrastructure
>>>> contains a definitive record of customers, application performance,
>>>> security threats, fraudulent activity, and more. Splunk takes this
>>>> data and makes sense of it. IT sense. And common sense.
>>>> http://p.sf.net/sfu/splunk-novd2d
>>>> _______________________________________________
>>>> Octave-dev mailing list
>>>> Octave-dev@lists.sourceforge.net
>>>> https://lists.sourceforge.net/lists/listinfo/octave-dev
>>>>
>>>>
>>>
>>> Hi all,
>>>
>>> The geomtry package also has functions to deal with polygons in 2D.
>>>
>>> Is there a chance that we merge the octclip and geometry package?
>>> At least it would be good to know what is already implemented in both
>>> packages and if possible benchmark them.
>>
>> Hi Pablo,
>>
>> The OctCLIP has only one function for performs general polygon
>> clipping using the Greiner-Hormann algorithm (see
>> http://davis.wpi.edu/~matt/courses/clipping/). I see that the geometry
>> package is the Octave implementation of MatGeom for MatLab that has
>> one function for polygon clipping when the clipper polygon is a
>> rectangular box and the clipped one is convex. The Greiner-Hormann
>> algorithm can work with general polygons so it could be used in the
>> clipping function in geometry. I see too that this function is not
>> implemented in the geometry package. But I would like to maintain
>> alive the OctCLIP package because for me is easier to maintain
>>
>> --
>> *****************************************
>> José Luis García Pallero
>> jgpall...@gmail.com
>> (o<
>> / / \
>> V_/_
>> Use Debian GNU/Linux and enjoy!
>> *****************************************
>>
>
> I see your point. I can suggest the following courses of action:
>
> 1. You accept to be a maintainer of the geometry package (which indeed
> is an extension of MatGeom since it handles piecewise polynomial
> polygons http://octave.sourceforge.net/geometry/function/shapetransform.html)
> and we merge the two packages. Geometry accepts a sub-folder
> structure, therefore you will continue maintaining ONLY the octCLIP
> folder. I can take care of the merging if you accept this proposal.
>
> 2. Geometry can add a wrapper that calls your function. This is clean
> but has the drawback that the user needs to install more packages and
> the dependency list grows.
>
> I strongly suggest 1. However I do not want you to feel that geometry
> is assimilating your package (we are not the Borg!). Geometry will be
> your package and your package will be everything else that geometry
> has. We will just clean up a little the repository and strengthen our
> packages.
>
> Looking forward to your answer.
OK, I can accept the option 1. But will be maintained the function
oc_polybool or will be substituted by clipPolygon from MatGeom? Take
in account that oc_polybool is more general that clipPolygon and if
you want to maintain the compatibility with clipPolygon from MatLab
some features will be lost.
I maintain a repository for OctCLIP in bitbucket:
https://bitbucket.org/jgpallero/octclip/
--
*****************************************
José Luis García Pallero
jgpall...@gmail.com
(o<
/ / \
V_/_
Use Debian GNU/Linux and enjoy!
*****************************************
------------------------------------------------------------------------------
All the data continuously generated in your IT infrastructure
contains a definitive record of customers, application performance,
security threats, fraudulent activity, and more. Splunk takes this
data and makes sense of it. IT sense. And common sense.
http://p.sf.net/sfu/splunk-novd2d
_______________________________________________
Octave-dev mailing list
Octave-dev@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/octave-dev
