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From Wail Alkowaileet <wael....@gmail.com>
Subject Re: Will it go 'round in circles?
Date Mon, 10 Aug 2015 15:30:47 GMT
Hi Till,

I'm not a "GIS-guy" but I used JTS to do simple geospatial operations
(mainly point-in-polygon). I know JTS is under LGPL and their specification
AFAIK is mapped to http://geojson.org/geojson-spec.html which under some
standard format: https://en.wikipedia.org/wiki/DE-9IM#Standards



On Sun, Aug 9, 2015 at 3:19 AM, Mike Carey <dtabass@gmail.com> wrote:

> I like the proposal that - for the "simple JSON" - everything has a single
> string format.
>
>
> On 8/8/15 12:13 AM, Chris Hillery wrote:
>
>> Ok, sounds like the consensus is that we want to keep circle. That's fine
>> with me. To bring the conversation full circle (narf!), now the question
>> goes back to how best to represent that type in JSON, given that the
>> obvious options don't support it... but, that conversation should continue
>> on the original thread.
>>
>> Thanks!
>> Ceej
>> aka Chris Hillery
>>
>> On Fri, Aug 7, 2015 at 10:41 PM, Chen Li <chenli@gmail.com> wrote:
>>
>> I second Ted's argument.  The reason on
>>> http://forums.mysql.com/read.php?23,148162,152625#msg-152625 is very
>>> weak, since following that logic there will be no 100% lines or
>>> rectangles on the surface of the earth.  But these shapes are very
>>> useful.
>>>
>>> I am sure there are use cases for circles, such as the Apple's new
>>> headquarters.  A related question is: what's the overhead of
>>> implementing and maintaining this type?
>>>
>>> Chen
>>>
>>> On Fri, Aug 7, 2015 at 2:04 PM, Ted Dunning <ted.dunning@gmail.com>
>>> wrote:
>>>
>>>> There you go.
>>>>
>>>> Another application.
>>>>
>>>>
>>>>
>>>> On Fri, Aug 7, 2015 at 1:43 PM, Mike Carey <dtabass@gmail.com> wrote:
>>>>
>>>> AND:  What if NASA wants to use us to store its database of crop
>>>>>
>>>> circles?
>>>
>>>> :-)
>>>>>
>>>>> On 8/7/15 11:47 AM, Ted Dunning wrote:
>>>>>
>>>>> On Fri, Aug 7, 2015 at 3:23 AM, Chris Hillery <chillery@hillery.land>
>>>>>> wrote:
>>>>>>
>>>>>> I've noticed that several geospatial serialization formats (at least
>>>>>>
>>>>>>> "well-known text" and GeoJSON) omit "circle" from their list
of basic
>>>>>>> geometric forms, even when they have numerous more complex types
such
>>>>>>>
>>>>>> as
>>>
>>>> multi-curves. This led me to here:
>>>>>>> http://forums.mysql.com/read.php?23,148162,152625#msg-152625
>>>>>>>
>>>>>>> which offers a reasonably compelling argument for why "circle"
is not
>>>>>>>
>>>>>> a
>>>
>>>> reasonable shape to discuss in geospatial contexts (loosely, because
>>>>>>> there's no consistent way to map that to a spherical coordinate
>>>>>>>
>>>>>> system).
>>>
>>>> Actually, that argument is super-weak.  It also implies that you
>>>>>>>
>>>>>> shouldn't
>>>>>> have lines (they aren't straight after projection) or squares (they
>>>>>>
>>>>> aren't
>>>
>>>> square after projection). But lines and squares both before and after
>>>>>> projection are very handy.
>>>>>>
>>>>>> Circles are useful in many contexts. Drawing the visible horizon
for a
>>>>>> particular observer is a great example.  The flight range of an
>>>>>>
>>>>> airplane
>>>
>>>> is
>>>>>> another case.  Positional error bounds with Gaussian errors is
>>>>>> another.
>>>>>>
>>>>>> Yes. You can approximate it using splines or polygons.  But you can
>>>>>> approximate anything that way.
>>>>>>
>>>>>>
>>>>>>
>


-- 

*Regards,*
Wail Alkowaileet

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