Jacques, I missed your original post, but I've just re-read it now.
I do believe that migs and other grids are registered correctly. The tab file gives registration coords for all 4 corners of the grid, and the coords refer to the top left corner of the referenced grid cell. Thus the cell coords of the bottom left corner are for row and col 1 greater than the real dimensions of the grid. This seems confusing, but does not mean that MapInfo is doing anything wrong. To echo what Jaromir Svasta said, I do dislike mig format because of its poor performance with large grids. VM grids perform much better for sequential (eg. display) and random (eg. info tool) access, which has to do with the way that migs are stored (I presume they are stored as compressed tiles within the mig file). And to echo what Stefan Matjan has said, you can do many things with grids in MapInfo without using Vertical Mapper. The catch is that you do need some other software (either 3rd party or home-baked). Like Stefan, I have invested considerable time in developing an extensive suite of grid processing tools using just C++ and the MapInfo grid engine (and a lot of work). In the course of that work, I also developed a grid format handler which allows you to write to Vertical Mapper grids directly from MapInfo - I hope to make this freely available in the near future. Best Regards, Martin Higham Avantra Geosystems ph (61 3) 8504 0428 0425-730-428 fx (61 3) 9596 7997 www.avantra.com.au > -----Original Message----- > From: Jacques Paris [mailto:[EMAIL PROTECTED] > Sent: Wednesday, 3 March 2004 23:51 > To: MIL > Subject: MI-L sum : MIG fantasies > > > I put SUM in the subject but it is a misnomer because SUM = 0 (ziltch) > > As I had already touched on the subject at least 2 years back and got the > same (lack of) reaction I have to choose between two possibilities > > 1 - that whatever I say is never challenged because I know the subject and > nothing has to be added- and that I do not accept > > 2 - that the MI adventure in GRID-mig files is seen as very unimportant by > MI users because MI did not put into it enough energy to make it an > interesting tool - and that, I am more inclined to accept. > > There are those who would say "But why worry? VM is there" They should > however be very concerned about what they will get. In fact what they are > already getting (beside a hefty bill, compared to a free GRID) is as > unreliable (if differently) relatively to grid registration as I > have noted > for a MIG. That we are in both cases dealing with "images" is not a reason > to wave off their reliable registration > > I am willing to drop the issue but not without warning you a last > time about > those unacceptable poor performances > > Jacques Paris > e-mail [EMAIL PROTECTED] > MapBasic-MapInfo support http://www.paris-pc-gis.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: 10680 > > --- > Incoming mail is certified Virus Free. > Checked by AVG anti-virus system (http://www.grisoft.com). > Version: 6.0.587 / Virus Database: 371 - Release Date: 12-02-2004 > --- Outgoing mail is certified Virus Free. Checked by AVG anti-virus system (http://www.grisoft.com). Version: 6.0.587 / Virus Database: 371 - Release Date: 12-02-2004 --------------------------------------------------------------------- List hosting provided by Directions Magazine | www.directionsmag.com | To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED] Message number: 10702
