[Mapserver-users] Map Extent

[Eric Bridger]

Thanks Lowell, but just to clarify, Ed McNierney already cleared this up
for me. The problem had to do with the fact that my map extents and
image size did not have the same aspect ratio. (x/y) should match
(lon/lat).

On Thu, 2003-02-06 at 15:13, Lowell Filak wrote:
> I think because your x extents are negative you need to change '$x = $imgext[0] + $cx*$x;' to '$x = $imgext[0] - $cx*$x;' or '$x = $imgext[0] + abs($cx*$x);'.
> The original code was developed for Minnesota & stateplane so a negative was not required.
> HTH
> Lowell F.
> 
> The following message was sent by Eric Bridger <eric at gomoos.org> on 03 Feb 2003 13:45:39 +0000.
 
> 
> > When adding a point symbol to the map at the location clicked, the
> > symbol appears near where I expected but not exactly where I expected. 
> > The closer I click to the center of the map the closer the symbol
> > registers.  It appears to me that the y-coordinate is always on target,
> > but that the x corrdinate is off. The closer to the edges of the map,
> > the further off the x coordinate is.
> > 
> > Perhaps this has to do with the fact that the map created 400x300 goes
> > all the way from y=0 to y=400, but not from x=0 to x=300?
> > 
> > 
> > Par of the map file:
> > MAP
> > EXTENT -97.238976 41.619778 -82.122902 49.38562
> > SIZE 400 300