Hi Jörg, Yes I understand all that and use the longitude to calculate MGT offsets and Latitiudes for Declinations and so on …
I am fixing data - matching one set imported data from another source - and I also realize that I could use a good proximity routine (using the lon/lat and a distance to find other places). Couldn’t find anything in KB. Anyway thanks for the help and explanations. John... > G’day John, > >> On 10 Apr 2020, at 10:03 AEST, John J Foster via 4D_Tech >> <4d_tech@lists.4d.com <mailto:4d_tech@lists.4d.com>> wrote: >> >> Many of the values are similar like 141.235 or 141 3.23 and so on. > > Have a look at a world map with a grid and consider this: > > Geodata are shown in degrees and fractions of it and can be shown in > different formats like: > > 143.754 ° E = 143° 59.5755’ E = 143° 59’ 34.5358” E > > Look at 0° Longitude (Greenwich)! Going to the Right means you are going East > (+) and going to the Left means you are going West (-). > In both directions it ends at 180° (International Date Line). > > Recap: E = + (Plus); W = - (Minus) > > For Latitude take a look at the Equator. > When you travel north (N) (North Pole) you’re Positive (+), going South (S) > to Antarctica you’re negative (-) > > Means: N = + (Plus); S = - (Minus) > > Suggestion: store the data as REAL in decimal degree format and you should be > fine. > > Exercise: > Name the town where I’m located when my position is: > > - 30.30225° 153.1086° > > Cheers > Jörg ********************************************************************** 4D Internet Users Group (4D iNUG) Archive: http://lists.4d.com/archives.html Options: https://lists.4d.com/mailman/options/4d_tech Unsub: mailto:4d_tech-unsubscr...@lists.4d.com **********************************************************************
