This short ditty is a gem and should be framed for future reference. Thanks Lars...
neil -----Original Message----- From: Lars V. Nielsen, GisPro [mailto:[EMAIL PROTECTED] Sent: Wednesday, November 12, 2003 5:16 AM To: andre boessenkool Cc: Mapinfo-List Subject: Re: MI-L Projections - methods of correction Hi Andre, There are basically two simple options you can employ, dependent on the nature of the problem. #1. If the visual geographic location is right, but the projection is wrong, e.g. if you've digitized some elements into a new table but forgot to set the right projection, a simple "Save As" with a different coordinate system will do the trick. The coordinates will be recalculated from the old to the new projection. #2. If the coordinates are right, but the projection is wrong, you need to export the table to Mif/Mid, change the COORDSYS clause at the top of the MIF file to the right value, and re-import the table. This will move the objects visually, while maintaining the coordinate values. #2b: If the coordinates are right, but uniformly shifted by an amount, or scaled wrongly (e.g. meters instead of kilometers), you can add a TRANSFORM clause below the COORDSYS ditto, to solve that. The shift/scale is applied during import, and will not be remembered in the table, i.e. it'll not be present if the table is exported again. Please refer to the proper appendicies in the Pro manual for a thorough description of COORDSYS and TRANSFORM. If none of the above situations apply, you need to utilize a more powerful utility to do some rubber sheeting or similar procedures. >From what you write, you need to apply method #1. The scaling will fix itself when the data's reprojected. I.e., do a "Save As" and specifiy "Latitude/Longitude (WGS84)" as the new projection. If you've already applied method #2 errornously, you need to reverse this proces before you can apply method #1. I.e. back to NonEarth first. Best regards/Med venlig hilsen Lars V. Nielsen GisPro, Denmark http://www.gispro.dk/ http://www.gispro.biz/ ----- Original Message ----- From: "andre boessenkool" <[EMAIL PROTECTED]> To: "Mapinfo-List" <[EMAIL PROTECTED]> Sent: Monday, November 10, 2003 11:18 PM Subject: MI-L Projections > > After a long absence from Mapinfo and the MI crowd I am back with what > is probably a basic question: > > I've started a new map, without paying attention to the projection. > All the work I've done has been done in a non-earth environment, > although it should have been a proper global projection, like Lat/Long > WGS84. > > Quite a few hours work are in it now, and I want to change from > non-earth to WGS84 without doing it all over again, if possible. > > My table data were interpreted as meters, but should have been > interpreted as degrees. When I change to WGS84, my degrees become > hopelessly small; what should be read as 16.234 deg. is processed to > 0.00016234 deg. Is this a well-known error?? How can it be fixed?? > > andre boessenkool > > > --------------------------------------------------------------------- > List hosting provided by Directions Magazine | www.directionsmag.com | > To unsubscribe, e-mail: [EMAIL PROTECTED] > For additional commands, e-mail: > [EMAIL PROTECTED] > Message number: 9096 > > --------------------------------------------------------------------- List hosting provided by Directions Magazine | www.directionsmag.com | To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED] Message number: 9107 --------------------------------------------------------------------- List hosting provided by Directions Magazine | www.directionsmag.com | To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED] Message number: 9119
