[GRASS-user] add a centroid in the center of polygon

[Milton Ribeiro]

Dear all

thanks again for all your kindy support and discussions.

you clarified about issues and possibilities of deal with this job.

Pretty thanks

miltinho


2014-01-31 Moritz Lennert <mlennert at club.worldonline.be>:

> On 30/01/14 23:13, Markus Metz wrote:
>
>> On Thu, Jan 30, 2014 at 10:39 AM, Moritz Lennert
>> <mlennert at club.worldonline.be> wrote:
>>
>>> On 28/01/14 11:52, Markus Metz wrote:
>>>
>>>>
>>>> On Mon, Jan 27, 2014 at 9:38 AM, Moritz Lennert
>>>>
>>>>>
>>>>>
>>>>> Personally, I support MarkusN's idea of merging the two, if that's
>>>>> possible
>>>>> from the code point of view. I find it more intuitive to look for a
>>>>> module
>>>>> creating centroids...
>>>>>
>>>>
>>>>
>>>> IMHO it will be confusing if there is a flag to calculate the center
>>>> of mass, but centroids are then not always the actual center of mass,
>>>> in which case it is safer to assume that centroids are not the center
>>>> of mass.
>>>>
>>>
>>>
>>> Well, that's when you come from the GRASS perspective with a very
>>> specific
>>> meaning for 'centroids'. I think for most users centroids are the center
>>> of
>>> mass. So, I'm not sure that this will really be an issue of great
>>> confusion.
>>>
>>
>> Centroids, in the sense of v.centroids for which you request the
>> modification, are calculated in the very specific GRASS meaning of
>> 'centroids', i.e. they really must be inside the area for which they
>> are calculated. Moreover, the center or mass for two or more different
>> areas can be exactly the same.
>>
>
> I might have not been clear in my suggestion: I completely understand the
> nature of centroids in v.centroids. The idea of the suggestion was that for
> many people, the notion of "centroid" is more similar to what you propose
> in v.centerpoint. So, why not merge the two modules so that we have one
> module v.centroid which, by default, provides the v.centerpoint
> functionality, but via a flag provides the current v.centroid functionality.
>
> But at the same time, I think we have more important issues such as Python
> on Windows for example ;-), so I won't push this any further.
>
> Moritz
>
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