Hello Lars, Actually, the 32bit range is spread over a distance further that 40,000km as MapInfo's lat/lons coordinate systems can go beyond the degree limits of the real world. I seem to remember that the unit distance was around (just under) 20m. Certainly I have experienced cased where I have done some object processing in "lat/lon (WGS-84)" (road locality searches involving small buffers) and the results did not work out until I switched to a local system which had an inherently greater accuracy.
Regards, Warren Vick Europa Technologies Ltd. http://www.europa-tech.com -----Original Message----- From: Lars V. Nielsen (GisPro) [mailto:[EMAIL PROTECTED] Sent: 25 November 2004 12:26 To: Robert Crossley Cc: MapInfo List Subject: Re: MI-L Accuracy of an object variable? Hi Robert, The accuracy (or better: resolution) of any (feature) object in MapInfo is dependent on the relevant projection bounds. The wider the bounds, the poorer the accuracy/resolution. The worst accuracy is using a straight lat/long table, since it needs to accomodate 40000 km inside a 32 bit integer, resulting in a coordinate accurracy/resolution of > 1 centimeter/? inch. It's possible to control the bounds in a table, rendering higher accuracy, but I suspect the cosmetic "layers" to always use the general lat/long projection, rendering them as the poorer choice. So I'd go for a (temporary) table anytime if accuracy is a concern. Best regards/Med venlig hilsen Lars V. Nielsen GisPro, Denmark http://www.gispro.dk/ ----- Original Message ----- From: "Robert Crossley" <[EMAIL PROTECTED]> To: "MapInfo List" <[EMAIL PROTECTED]> Sent: Thursday, November 25, 2004 7:33 AM Subject: MI-L Accuracy of an object variable? Hi list, While on a few occasions there has been some discussion on the accuracy of putting an object into the cosmetic layer vs a table in terms of accuracy, any comment on loss of accuracy taking an object from a table, processing it as an object variable in memory and inserting it into another table from the object variable? r -- ________________________________________________ Robert Crossley Agtrix P/L 9 Short St PO Box 63 New Brighton 2483 Far Southern Queensland AUSTRALIA 153.549004 E 28.517344 S P: 02 6680 1309 F: New Connection M: 0419 718 642 E: [EMAIL PROTECTED] W: www.agtrix.com W: www.wotzhere.com --------------------------------------------------------------------- List hosting provided by Directions Magazine | www.directionsmag.com | To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED] Message number: 14223 --------------------------------------------------------------------- List hosting provided by Directions Magazine | www.directionsmag.com | To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED] Message number: 14227 --------------------------------------------------------------------- List hosting provided by Directions Magazine | www.directionsmag.com | To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED] Message number: 14230
