> Is there another free tool I could use to calculate projected > sense, is it even something you can convert like feet to > the GEODIST function on (I admit I'm not sure that even ![]() > have my new coordinates changed to projected ones that I > they are vastly different (by like 20% or more). When I compare two points that should be the same > using ArcGIS and a projected coordinate system (not > set of distance calculations on a similar set that were > distance between every point in the sets. > I have two sets of GPS coordinates and I need to calculate the > but not what I need to do to make GEODIST match ArcGIS. > going to be different, and how to make ArcGIS match SAS's GEODIST, > On Fri, at 10:02 AM, Sally Vegso > wrote: > ArcGIS is using - but I think that's supposed to be similar to the Geodesic > You could also check the Haversine distance and make sure that's not what > don't know exactly how ArcGIS implements this but I suspect someone else > multiplied by the cosine of latitude as you move away from the equator. > 1 longitude is about the same at the equator (69.172 mi), and then is > 1 latitude = 69.047 statute miles = 60 nautical miles = 111.12 kilometers > So, sqrt((X2-X1)^2 + (Y2-Y1)^2) = Euclidean distance in degrees, then ![]() ![]() > according to an answer on this (the bottom one): > miles at the equator, perhaps?) This seems to be how it's calculated, > calculating the euclidean distance (just convert lat/long difference to > geodesic distance is what SAS Geodist is calculating. > Is your data like the first table? Point of that paper is that ArcGIS RPyGeo - interfaces with ArcGis, may be able to get an old inexpensive Too many ways to calculate distances, Seal Level, cruise missile, elipsoid I have my doubts that you can get SAS, R or Python to duplicate ArcGis, I am a little out of my comfort zone on this topic but: Message-ID: CAOUdXL_BkpN5j7+v3xYLJpvoLiydM=sKAyX5qvXZopvzTX_faQ () mail ! gmail ! com
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