[mapserver-users] Mapserver and Spatial Extent
   
    James Anderson
     
    james@danisat.net
       
    Fri, 30 Aug 2002 10:02:45 +0200
    
    
  
Hi,
I need to know more about the EXTENT command in a Mapserver map file.   I
have a shape file layer of Kampala.  The shapefile is in WGS 84 projection.
The center of the Shapefile is lat=32.5747819077374 and
lon=0.320786584028765   I need to know how to work out the Extent values
from the lat and lon.  My map file looks like this
NAME EX1
EXTENT   ???? ???? ???? ????
SIZE 600 600
SHAPEPATH "C:\Documents and Settings\Steed\My Documents\mapping\kampala\shp"
PROJECTION
    "proj=longlat"
    "ellps=WGS84"
    "datum=WGS84"
    "no_defs"
END
LAYER
  NAME "Kampala"
  DATA kampala
  STATUS DEFAULT
  TYPE LINE
  CLASS
    COLOR 250 175 25
  END # end of class object
END # end of layer object
END # end of map file
If need to work out the values to put in by the ????s.   I need some
formulas.  When I put some random values in the extent, the mapserver
produces an image, yet it is plain white.  I believe that this is because I
have the extent set to where there is no mapping data.  I am still very new
to using this mapserver.  I may have other errors in my map file.  I need to
get this mapping to work.  Can anyone help ??
Thanks,
James.