Strange behavior ....

[Daniel Morissette]

JF,

We have an application that does something similar to yours: we display
a layer of points in LAT/LON on top of a base map in LCC and we noticed
the same thing as you.  We haven't investigated the problem yet,
though...

Steve, are you aware of any PROJ.4 limitations that could explain that
behavior?  It seems to be that LAT/LON points located north of a
specific latitude are lost.  And the latitude at which points starts to
disappear changes depending on the scale of the map: as you zoom in, the
line where points start to disappear moves north.

Any idea?

Daniel

"Doyon, Jean-Francois" wrote:
> 
> Hello !
> 
> Well, things are oging pretty well, but now I've run accross a strange
> behavior
> I was hoping someone could explain ...
> 
> When I map my search results (using php-mapscript as allways), I create
> atemporary shapefile.
> This shapefile use geographical coordinates, whereas the rest of the data
> used to generate the
> map uses a different projection (lcc to be exact).
> 
> Now for some reason, results don't seem to show up in the far north
> (Nunavut) !
> Actually, they do show up, but only once I zoom in ! Now, I am *NOT* doing
> anything to that layer
> that might do this, the layer is "ON" by default, and that's it. All the
> Other symbols show up.
> Actually results in Iqualuit show, but not other smaller Nunavut communities
> ... Until I zoom in.
> 
> I'm wondering why this might be, and how to fix it ... I'm guessing the
> projection conversion might
> have something to do with it ? But that's out of my area of expertise ...
> 
> Any ideas ?
> 
> Thanks,
> 
> Jean-Francois Doyon
> Internet Service Development and Systems Support
> GeoAccess Division
> Natural Resources Canada
> (613) 992-4902

-- 
------------------------------------------------------------
 Daniel Morissette                       danmo at videotron.ca
              http://pages.infinit.net/danmo/
------------------------------------------------------------
  Don't put for tomorrow what you can do today, because if 
      you enjoy it today you can do it again tomorrow.