[Mapserver-users] Can't seem to get the projection correct

[Martin, Daniel]

I want to thank everyone for all the responses.

Daniel Morissette hit the nail on the head.  MapInfo and Mapquest are indeed
doing some matter of x-scale adjustment to make maps "look better".  

I know this isn't scientific, but my maps in MapInfo look like I expect them
too.  For instance, my home state of Missouri that I've seen on maps
thousands of times "looks" like I know it to look in MapInfo.  In MapServer
it "looks squished".  I don't know how to express it any different than
that.  One way I've adjusted for it is to force a new aspect ratio in the
<img > tag on the HTML template to "squish" the image back.  But I hate that
solution.  It's not a good solution in my book.

I'm going to take a look into some things mentioned and see if I can get
anywhere.  I'll be sure to let you know how they turn out.

Thanks again,
Dan Martin



> -----Original Message-----
> From: Daniel Morissette [mailto:morissette at dmsolutions.ca]
> Sent: Tuesday, February 18, 2003 12:10 PM
> To: Martin, Daniel
> Cc: mapserver-users at lists.gis.umn.edu
> Subject: Re: [Mapserver-users] Can't seem to get the 
> projection correct
> 
> 
> "Martin, Daniel" wrote:
> > 
> > Sorry to correct you, but that's not true - at least not 
> since I've worked
> > with MapInfo (version 5 through 7). That may be an optional 
> configuration,
> > but by default MapInfo doesn't change the aspect ratio of 
> the data with the
> > window.  By default, the data's horizontal extent stays the 
> same as the
> > window is resized, but the vertical changes to maintain the 
> projection.
> > 
> 
> You're correct, I was wrong on that, I should have checked first.  I
> found the option that's causing this effect... open your lat/lon map,
> then select Map/Options, the "Distance/Area Using:" radio box 
> is set to
> Spherical.  Change the projection to "Non-Earth", and the
> "Distance/Area" will switch to cartesian, and then your map will look
> exactly as it does in MapServer.  
> 
> I'm not sure what this spherical distance option does exactly but it
> seems that MapInfo (and MapQuest) use this to adjust the 
> x-scale of the
> map to make it look better, that's why the map looks 
> different, this is
> not a projection effect, it's a map scaling effect.  Unfortunately at
> this point MapServer supports only maps with x-scale == y-scale (or
> square pixels if you like) so you won't be able to reproduce 
> that unless
> you can define a projection that produces a similar effect.
> 
> -- 
> ------------------------------------------------------------
>  Daniel Morissette               morissette at dmsolutions.ca
>  DM Solutions Group              http://www.dmsolutions.ca/
> ------------------------------------------------------------
>