Nice modification to Google Maps! P=) A suggestion: Why not include fields for Lat,Long submissions (perhaps just as decimal, but recognizing minutes and seconds as fraction parts——e.g., automatically convert "+42+30/60+36/3600" to "42.51")? Also, what are you using as a "great-circle radius"? I would suggest the ellipsoidal quadratic mean ("Qr"), which equals [.25*(3a^2 + b^2)]^.5 (for Earth, using WGS-84, where a = 6378.137 and b = 6356.752314, Qr ~=~ 6372.7975559 or just "6372.8", if you are rounding values to .1 km): See http://groups.google.com/group/comp.infosystems.gis/msg/5897cf05c924a569 for explanation why. Also——perhaps you might consider in the future——I have a relatively simple approximation for the "elliptic great-circle" distance (*maximum* error < +/-.4 m!), or parageodesic, which is similar to the geodesic, except that it is geographically delineated (e.g., for two antipodal points on the equator, the geodesic is along the north-south path, while the parageodesic can be along any path, even along the equator).
There was a good feature in the previous version: I could drag the end (begin) point on the map, move and drop it to a new place. However this function does not work anymore. :-(
Hello there!
ReplyDeleteNice modification to Google Maps! P=)
A suggestion: Why not include fields for Lat,Long submissions (perhaps just as decimal, but recognizing minutes and seconds as fraction parts——e.g.,
automatically convert "+42+30/60+36/3600" to "42.51")?
Also, what are you using as a "great-circle radius"? I would suggest the ellipsoidal quadratic mean ("Qr"), which equals [.25*(3a^2 + b^2)]^.5 (for Earth, using WGS-84, where a = 6378.137 and b = 6356.752314, Qr ~=~ 6372.7975559 or just "6372.8", if you are rounding values to .1 km): See http://groups.google.com/group/comp.infosystems.gis/msg/5897cf05c924a569 for explanation why. Also——perhaps you might consider in the future——I have a relatively simple approximation for the "elliptic great-circle" distance (*maximum* error < +/-.4 m!), or parageodesic, which is similar to the geodesic, except that it is geographically delineated (e.g., for two antipodal points on the equator, the geodesic is along the north-south path, while the parageodesic can be along any path, even along the equator).
~Kaimbridge~
There was a good feature in the previous version: I could drag the end (begin) point on the map, move and drop it to a new place. However this function does not work anymore. :-(
ReplyDeleteI will add drag and drop function soon :)
ReplyDeletethank you.
I liked the way you had your drag points before when all you needed was to grab and drag , would like3 to see that option back again :-)
ReplyDeleteThanks !!!!
hey ur showing direct direction .. we want a proper distance by road
ReplyDelete