Any decent world map will likely have latitude and longitude markings, there's a reference. There are occasions when working over the international date line a 0-360 system is used but most common 0 longitude is around Greenwich and ranges -180 to 180. Latitude systems don't vary AFAIK, they're -90 to 90. Don't worry about coordinates falling precisely on the edge, in practice it's
Evan Carroll, there are different ways of creating point objects, this is the first, second - SN Tiwari confused places with latitude and longitude values, it was necessary to pay attention to this, with respect –
Latitude is the Y axis, longitude is the X axis. Since latitude can be positive and negative (north and south of the Equator), and longitude can be as well (negative west of Greenwich and positive eastward) when the -180 to +180 longitude system is use. Hence the four combinations of positive and negative are possible depending upon where you ...
The equations as given return the length of a radian of longitude or latitude, respectively. To get the length of a degree instead, multiple each equation by: PI/180.0 As a check, the approximate length of a degree of longitude at the equator is 111 km as is the length of a degree of latitude everywhere (varies from about 110.5 to 111.7). The ...