On Dec 5, 4:59 am, "Map&EarthNewbie" <[EMAIL PROTECTED]> wrote:
> 1. Onhttp://en.wikipedia.org/wiki/Geographic_coordinate_system, it > states that "Baltimore, Maryland (in the USA) has a latitude of 39.3° > North, and a longitude of 76.6° West." Why was North and West > coordinates used to describe this location? Couldn't it have been > described in terms of South and West or South and East? It could have, but not with the standard lat/lon coordinate system that everyone uses. This defines all latitudes as north or south of the equator, and longitudes as east or west of the Prime Meridian. Intrinsically, these are no more valid than any other origin, but they are the standard. OK, I take that back, the equator is an intrinsically logical north/ south origin. > 2. Assume I have a bunch of latitude and longitude locations in my > database. Given North, East, West, and South coordinates, how could I > return all the map points that fall within the boundaries of those 4 > given coordinates? It gets complicated if your boundaries are near one of the poles, span the antimeridian, or cover a large section of the Earth's surface, but generally you'll simply look for database locations whose latitude is between your North and South boundaries, and whose longitude is between your East and West. In generic SQL: select * from locations where location.latitude between south and north and location.longitude between west and east; > Also, are latitude and longitude coordinates always: degrees, minutes, > seconds followed by North, East, West, or South? No, they can also be expressed in terms of decimal degrees, a more logical system and the one used by Google Maps. See http://en.wikipedia.org/wiki/Decimal_degrees for more info. String --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "Google Maps API" group. To post to this group, send email to [email protected] To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/Google-Maps-API?hl=en -~----------~----~----~----~------~----~------~--~---
