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Re: CRS best practices: Google Geocoding API

From: Jeremy Tandy <jeremy.tandy@gmail.com>
Date: Fri, 03 Mar 2017 15:55:36 +0000
Message-ID: <CADtUq_1Qzt8xts-24Rkwt4FOL2QXQoNA7ePnwj=_mVk3X5K_NQ@mail.gmail.com>
To: Clemens Portele <portele@interactive-instruments.de>
Cc: SDW WG Public List <public-sdw-wg@w3.org>, Ed Parsons <eparsons@google.com>
Hmmm. Are you suggesting being human isn't enough :)

> Don’t forget radian or gon which are used in practice as units for
angles, too, but are also floating point numbers

That does add to the complexity. The CRS best practice needs to ensure
we're explicit on the choice of units too.

Jeremy

On Fri, 3 Mar 2017 at 15:52 Clemens Portele <
portele@interactive-instruments.de> wrote:

Being a human, I'm prepared to guess that these are decimal degrees
(because they look like floating point numbers). Easy for machines to
figure that out too.


Don’t forget radian or gon which are used in practice as units for angles,
too, but are also floating point numbers :)

Clemens


On 3 Mar 2017, at 16:14, Jeremy Tandy <jeremy.tandy@gmail.com> wrote:

Hi Ed- in the introductory material you wrote about CRS you make a
reference to the Google Geocoding API [1], in that its responses explicitly
state Lat and Long rather than a coordinate pair of ambiguous order.

Lat and Long are, by definition, angular measurements. OK - got that.

But parsing through the API documentation, I can't see any reference to the
units or datum which is used.

Being a human, I'm prepared to guess that these are decimal degrees
(because they look like floating point numbers). Easy for machines to
figure that out too.

As a human, I'm also prepared to guess that the API uses the WGS84. But
that is a tricky leap for machines to work out.

Does the API documentation say "WGS84" anywhere? If so, can you point me to
it so I can refer to this explicitly? And if not, can you either justify
why it doesn't matter, or get your colleagues to update the documentation
(and then send me a link!).

(I think that we've all agreed that it's dangerous to _assume_ a CRS :-) )

Thanks, Jeremy

[1]: https://developers.google.com/maps/documentation/geocoding/intro
Received on Friday, 3 March 2017 15:56:20 UTC

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