[Tagging] Let's get (quite) rid of units and their multiples in OSM values

Richard Welty rwelty at averillpark.net
Fri Jul 27 16:51:45 UTC 2018


normalization into SI is the sort of thing that engineers and scientists
go for, and speaking as a (computer) scientist it has some appeal.

but practically it's probably not a good idea in mapping, where i think
we should be using local units in an unambiguous manner.

if i see maxspeed=40 on a road in the US w/o units, i have no idea what
i'm looking at, it could be 40mph or it could be 25mph. the mapper who
entered the data knew what s/he was looking at but i sure don't.

richard

On 7/27/18 11:20 AM, marc marc wrote:
> I agree maybe with the exeption of case like maxspeed
>
> François voltage is a good usecase to open an issue to the whised app.
>
> Le 27. 07. 18 à 14:19, Andrew Hain a écrit :
>> My own preference is to have no (zero) units in the database, decimals 
>> where wanted (maxwidth=2.2) and unit management support in editors.
>>
>> --
>> Andrew
>> ------------------------------------------------------------------------
>> *From:* Warin <61sundowner at gmail.com>
>> *Sent:* 27 July 2018 12:27:04
>> *To:* tagging at openstreetmap.org
>> *Subject:* Re: [Tagging] Let's get (quite) rid of units and their 
>> multiples in OSM values
>> On 27/07/18 21:11, Martin Koppenhoefer wrote:
>>> sent from a phone
>>>
>>>> On 26. Jul 2018, at 21:26, François Lacombe <fl.infosreseaux at gmail.com> wrote:
>>>>
>>>> I don't want to break things but only improve them, all the best
>>> one issue with using only one unit for a tag is that they can’t always be transformed without rounding. E.g. maxspeed=55mph cannot be converted to kph without losing information
>>>
>>> Also, shorter notations are better readable, hence reduce the likeliness of errors not noted.
>>>
>>> On the other hand, I agree in the example of voltage it would make it easier for queries to use the same unit. (you still can make queries, but they are more complicated if you have to take units into account)
>>>
>>>
>> Unfortunately not everyone uses the same units... heights are in meters, 
>> feet .. depending on where you come from or what activity you follow.
>>
>> Voltages are in volts so the same units... but multiplies are common for 
>> high voltages .. no one uses 33000 volts .. they all use 33 kv.
>> If you stipulate that all voltages have to be in kv then 115 v becomes 
>> 0.115 kv, 240 v becomes 0.24 kv and 415 v becomes 0.415 kv ..
>> that is not how people talk about these things.
>>
>>
>>
>> _______________________________________________
>> Tagging mailing list
>> Tagging at openstreetmap.org
>> https://lists.openstreetmap.org/listinfo/tagging
>>
>>
>> _______________________________________________
>> Tagging mailing list
>> Tagging at openstreetmap.org
>> https://lists.openstreetmap.org/listinfo/tagging
>>
>
> _______________________________________________
> Tagging mailing list
> Tagging at openstreetmap.org
> https://lists.openstreetmap.org/listinfo/tagging


-- 
rwelty at averillpark.net
 Averill Park Networking - GIS & IT Consulting
 OpenStreetMap - PostgreSQL - Linux
 Java - Web Applications - Search




More information about the Tagging mailing list