Given that SI units are standard across OSM could be define a "speed" value in addition to "Numeric" "String" etc like so: (default to kmh as specified before (also means not adding millions of pointless "kmh" strings to the db) Factor means "multiply by this to convert to SI - interpreters would either use value as-is or multiply by Factor for that suffix to get SI units. "Suffix" is the entire string after the numerical value, with whitespace trimmed - so spaced/not spaced suffix wouldn't matter - defining this rigidly would be ignored by most users, i suspect
My proposed table: Unit - Factor "" - 1 "kmh" - 1 "mph" - 1.609 "knots" - 1.852 Not sure if any other units are in (common) use? Can someone check tagwatch? Tristan 2008/10/14 Matthias Julius <[EMAIL PROTECTED]> > "Tristan Scott" <[EMAIL PROTECTED]> writes: > > > If it were up to me (dicatorships are so much swifter to deal with > > things...) > > * maxspeed should be the only tag. Therefore you can't contradict > > yourself/others (or update one to 40mph, or not catching because it's not > > normal, maxspeed:mph is still 30 you end up with broken data) > > * "mph" is the only permittable suffix (or a SHORT fixed list added to > map > > features), therefore parsing is simple. If Mph / MilesPerHour / mp/h / > > yard/minute / walk / et al is allowed then parsing becomes either > impossibly > > (inf types of value) difficult, or becomes easy (if it's not all numeric, > > ignore it). > > The list doesn't need to be very short, but it needs to be defined > somewhere. Then, any application that uses the data can be taught how > to deal with it. > > Then Map Features needs to specify that maxspeed is a speed > measurement and link to the table of speed units. > > Then Maplint can be extended to recognize tags that require a speed > unit and it can warn if there is none. > > Matthias > > _______________________________________________ > talk mailing list > talk@openstreetmap.org > http://lists.openstreetmap.org/listinfo/talk > -- Tristan Scott BSc(Hons) Yare Valley Technical Services www.yvts.co.uk 07837 205829
_______________________________________________ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk
