reading grid cells using geographic coordinates.

[Sergi Gàmiz Ribelles]

Hello. Here again with another problem: accessing a grid via mapbasic given a position on the map returns the correct pixel value if coordinates are UTM but returns another pixel if coordinates are geographical (longitude / latitude). Does someone know how to solve this problem?
Thank you very much.

[Daniel Wiens]

Does this have something to do with orientation??? of pixels changing when moving from UTM to Lat/Long.  When I change from UTM to Lat/Long I notice an image is squished (great GIS terminology I'm sure)???  I try to always remain in UTM where everything is "square" and only change to Lat/Long when it's the last thing I do (usually when making customer deliverables.  The software is supposed to correct for this - but I don't trust it.

On Tue, Sep 20, 2022 at 8:09 AM Sergi Gàmiz Ribelles <sector_...@iies.es> wrote:

Hello. Here again with another problem: accessing a grid via mapbasic given a position on the map returns the correct pixel value if coordinates are UTM but returns another pixel if coordinates are geographical (longitude / latitude). Does someone know how to solve this problem?
Thank you very much.

--
--
You received this message because you are subscribed to the
Google Groups "MapInfo-L" group.To post a message to this group, send
email to mapi...@googlegroups.com
To unsubscribe from this group, go to:
http://groups.google.com/group/mapinfo-l/subscribe?hl=en
For more options, information and links to MapInfo resources (searching
archives, feature requests, to visit our Wiki, visit the Welcome page at
http://groups.google.com/group/mapinfo-l?hl=en

---
You received this message because you are subscribed to the Google Groups "MapInfo-L" group.
To unsubscribe from this group and stop receiving emails from it, send an email to mapinfo-l+...@googlegroups.com.
To view this discussion on the web visit https://groups.google.com/d/msgid/mapinfo-l/e314f81f-e2e0-4487-bd88-0d058fb91a0bn%40googlegroups.com.

[Sergi Gàmiz Ribelles]

Thank you. Don't you know any math operation to correct it?

El dia dimarts, 20 de setembre de 2022 a les 19:59:39 UTC+2, D...@cropview.net va escriure:

[Sergi Gàmiz Ribelles]

SOLVED.  I have solved this issue by means of a subroutine that transforms geographic coordinates to UTM using geodetic calculations. Then reading grid cells and subsequent calculations are in UTM coordsystem.

SGR

El dia dimecres, 21 de setembre de 2022 a les 15:30:39 UTC+2, Sergi Gàmiz Ribelles va escriure: