[FWTools] Big NTv2-Grid-File causes problem

[Frank Warmerdam]

Ernst Meier wrote:
> Frank,
> 
> the filesize ist about 40MB (gs_count 25000000)
> There is no error message - only a bad coordinate as i wrote earlier.
> 
> In this document (http://www.geom.unimelb.edu.au/gda94/SoftDoc.pdf) i found on page 28 that the size of an subgrid is an %6d integer. Therefore i think 999999 is the maximum for gs_count.
> 
> It's only a guess, so you may correct it.

Ernst,

OK, well there can be many reasons for a coordinate transforming differently
than expected.  I looked at the header reading code, and the gs_count is
stored in the NTv2 header as a 4 byte binary integer, so there should be
no issues until it gets to 2^31.

Best regards,
-- 
---------------------------------------+--------------------------------------
I set the clouds in motion - turn up   | Frank Warmerdam, warmerdam at pobox.com
light and sound - activate the windows | http://pobox.com/~warmerdam
and watch the world go round - Rush    | Geospatial Programmer for Rent