Hi, I posted an email on this issue a month ago. Here it is again.
************************************************************ I have seen this thing as well and the explanation to my problem was different bounds on the two tables projections !! If the tables have different projections the bounds might also differ. If there is a big difference in the bounds, there is also a big difference in the resolution of the "coordinate grid" in the table. Fore instance: If you have a projection covering the whole world, the resolution is: 1/1000000 of a degree (about 11 cm at the equator or along a meridian). If you alter your bounds on the projection you might get a precision of 1 or 2 cm. And here is the tricky part: If you are drawing in a table with a precision of 11 cm you are very well able to snap to objects from the table with the precision of 1-2 cm, but in most cases the point you snap to is rounded to fit into the precision of 11 cm !!! ************************************************************ Could this be causing your problems as well ? Peter ------------------------------------------------------------------------------------------------ Peter Horsb�ll M�ller, GIS Udviklingskonsulent / GIS-Developer Kampsax A/S - GIS Software & Solutions Rugaardsvej 55, 5000 Odense, DK tel: +45 6313 5013, dir:+45 6313 5008, fax: +45 6313 5090 mailto:[EMAIL PROTECTED] www.kampsax-gis.dk and www.kampsax.dk Authorized MapInfo Partner & Distributor in Denmark and Norway. ------------------------------------------------------------------------------------------------ Se mere om Dansk MapInfo Brugerkonference p� http://www.kampsax-gis.dk/Default.asp?ID=296 Klik ind p� http://www.kortal.dk og se det hele lidt fra oven! Check http://www.kortal.dk and have a look at Denmark from above! ----- Videresendt af Peter M�ller/Kampsax - 16-08-2002 07:48 ----- itssa@itssacons ulting.com Til: <[EMAIL PROTECTED]> cc: <[EMAIL PROTECTED]> 16-08-2002 Vedr.: Re: MI-L Snapping polylines to Points programmatically - doesn't 00:59 work Besvar venligst til itssa Martin, At least I found other people with my problem !. :-) Just I can say you the issue is not related NZ position in the world because in my case, I am working with WGS84 and bounds for Argentina and I have the same problem. I sent this issue to Mapinfo Technical support almost 2 years ago and I never have obteined any answer. In my case is CRITICAL ! not solve this problem because I need to work with this coordinate system URGENTLY and I can't see any solution. Also I worked with Gauss-Grugger system coordinate and it works perfectly. Please if you find the solution I will appreciate a lot if you comment it me !. I will do the same.- regards alejandro Martin Roundill <[EMAIL PROTECTED]> : > The issues that have been raised recently (refer MI-L Cosmetic Precision - > Big problem) are ones that I am currently struggling with. > > I use a mapbasic code routine to snap lines to point features. The routine > searches for a point feature, grabs it coordinates and updates the node of > the line. This all works fine but when I then update the original polyline > record with the revised object MapInfo appears to randomly change the end > point of the line. I have even written a debug routine to check this - the > routine alters the coordinate of a polyline, updates the record then queries > the node on the updated polyline and 9 times out of 10 it is not the same. > > I know that this is not due to projection accuracy issues as I have tested > this exhaustively. I know this is not due to my logic as again I have > tested this (over and over and over!!!) > > One of the weird things about this error is that each time I run exactly the > same code on exactly the same data I get different results and if I run it > long enough sometimes the polylines will correctly update. > > The only thing I can think of is that > a) it is a MapInfo bug > b) it is related to the projection engine that deals with my region > of the world (New Zealand) > > Other developers must have had this problem before! But I cannot find any > references to this is the archives. > > I have been developing in MapInfo/MapBasic for 7 years so I am confident I > have covered all bases in terms of the problem being the logic of my code. > > Anyone got any ideas? > > > > Martin Roundill > GIS and WEB MANAGER, IM (Ext 8344) > Providing effective coordinated and independent expertise, supporting all > Council's operational and strategic information management requirements. ___________________________________ NOCC, http://www.coopenet.com.ar --------------------------------------------------------------------- List hosting provided by Directions Magazine | www.directionsmag.com | To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED] Message number: 2548 --------------------------------------------------------------------- List hosting provided by Directions Magazine | www.directionsmag.com | To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED] Message number: 2555
