Speeding up load time for huge SHP files

[Frank Warmerdam]

Efren Serra wrote:
> Guys,
> 
> Thanks for the feedback.  Do you folks know of a way to generate Maps
> centered on the International Date-Time Boundary?

Efren,

There are a few approaches to this.

1) You could do all your work in an appropriate local projected
coordinate system.  If all your data is in this projection and it
behaves well at the dateline then there should be no problem.

2) You can do all your work in a geographic coordinate system (ie.
everything is lat/long) and use coordinates in the range 0 to 360
instead of -180 to 180.   Getting your data into this form ahead
of time can be challenging.

The above are "easy" cases as long as you can pre-cook things.  But if
you need dynamic reprojection then things get more complex because for
the most part MapServer and PROJ.4 don't understand about wrapping at
the dateline.  This can confuse the queries against datasources in a
different projection, as well as messing up rendering of some features
that cross the dateline.

If you can't follow (1) or (2) then I would suggest you be very specific
about what you want to do and in fact, do some experimentation yourself
before coming back to ask questions.  For instance, the issues vary
depending on whether the input data is raster or vector, whether you
are producing output in geographic vs. projected space, whether you want
"whole world" views or just a local area near the dateline, etc.

Best regards,

-- 
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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    | President OSGeo, http://osgeo.org