[mapserver-users] Problems mapping regions that span Dateline

[Roger André]

Hi Brent,

Thanks for your reply.  Converting to a 0 - 360 longitude span seems
like it would work, but as part of my map contains imagery data, I
think it would probably be best if I could define a new projection in
my epsg file that contained the required parameters.  Is that
possible?  I have implemented the DateLine wrap in OpenLayers, and it
works well there.  Unfortunately, I also need to generate some map
images dynamically via mapscript, and this is where I have the most
problems.

Thanks again,

Roger
--

On Thu, Mar 5, 2009 at 1:54 PM, Brent Wood <pcreso at yahoo.com> wrote:
>
>
> Welcome to my world...
>
>
> The simplest way is, if you can, convert your longitutes to a 0-360 instead of +-180 space. If you use PostGIS the shift_longitude function works, Proj.4 can also be told which space to use for western hemisphere longitudes and generate longs in the 0-360 space.
>
> Alternatively, if you stick to +-180, you can use OpenLayers at the client end, as this has a switch available to work across 180.
>
>
> HTH,
>
>  Brent Wood
>
>
> --- On Fri, 3/6/09, Roger André <randre at gmail.com> wrote:
>
>> From: Roger André <randre at gmail.com>
>> Subject: [mapserver-users] Problems mapping regions that span Dateline
>> To: "mapserver-users at lists.osgeo.org" <mapserver-users at lists.osgeo.org>
>> Date: Friday, March 6, 2009, 8:30 AM
>> Hi All,
>>
>> I'm having some problems mapping some regions of the
>> world that span
>> the Dateline.  I have several examples of this, but using
>> one, the UN
>> subregion defined as being "South Pacific", as an
>> example illustrates
>> the problem nicely.  This region has the following extents:
>>
>> Corner Coordinates:
>> Upper Left  (-180.0000000,  28.2333333)
>> Lower Left  (-180.0000000, -29.0666667)
>> Upper Right ( 180.0000000,  28.2333333)
>> Lower Right ( 180.0000000, -29.0666667)
>>
>> The map that is generated using these extents with EPSG
>> 4326 spans the
>> entire globe, and I'd like to find a way to show the
>> are in a more
>> concise fashion.  I have the same problem with New Zealand,
>> and with
>> the full extents of the USA.
>>
>> Hoping for some suggestions.
>>
>> Thanks,
>>
>> Roger
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>