As Dershowitz and Reingold showed in their book "Calendrical Calculations",
converting from UTC to several calendars needs latitude, longitude, and
elevation.�� ISO 6709 is the relevant standard:

On Tue, 4 Dec 2018 at 23:35, C��drick B��ler <cdrick65@gmail.com> wrote:
Interesting.

I���m interested with such tools too.

I ask students to do gps point collection from mobile (Cordova) and process them in pharo to detect if they enter known places.

I wonder if a proper gps point class would be useful. I���d like to record also the precision.

Cheers,

Cedrick



> Le 4 d��c. 2018 �� 11:15, Alistair Grant <akgrant0710@gmail.com> a ��crit :
>
> Hi Sven,
>
> Thanks.�� This is just for me playing around with my photo collection,
> i.e. find all photos from a particular location, i.e. within a
> specified distance of a point.�� Also maybe add GPS coordinates to some
> photos.
>
> Thanks again,
> Alistair
>
>> On Tue, 4 Dec 2018 at 11:04, Sven Van Caekenberghe <sven@stfx.eu> wrote:
>>
>> Hi Alistair,
>>
>>> On 4 Dec 2018, at 10:21, Alistair Grant <akgrant0710@gmail.com> wrote:
>>>
>>> Hi,
>>>
>>> Does anyone know of a library for processing GPS coordinates?
>>>
>>> What I'm looking for are things like:
>>>
>>> - Parsing from and printing to various string formats (HMS, NESW, decimal)
>>> - Distance between two points
>>> - etc.
>>>
>>> Thanks,
>>> Alistair
>>
>> We've got some elementary stuff based on WGS84 coordinates as points. For example,
>>
>> T3GeoTools distanceBetween: 5.33732@50.926 and: 5.49705@50.82733.
>> T3GeoTools bearingFrom: 5.33732@50.926 to: 5.49705@50.82733.
>> T3GeoTools destinationFrom: 5.33732@50.926 bearing: 45 distance: 2500.
>> T3GeoTools centroidOf: { 5.48230@50.82249. 5.49523@50.81288. 5.50138@50.82008. 5.50228@50.82595. 5.49265@50.82560. 5.48230@50.82249 }.
>> T3GeoTools is: 5.33732@50.92601 inside: { 5.48230@50.82249. 5.49523@50.81288. 5.50138@50.82008. 5.50228@50.82595. 5.49265@50.82560. 5.48230@50.82249 }.
>>
>> This is not open source, but it is not rocket science either (just implementations of public algorithms).
>>
>> We have less need for special conversions, we do them case by case when they occur.
>>
>> What are you planning to do ?
>>
>> Sven
>>
>>
>