[mapguide-dev] area calculation conversion to meters

[Daniel Morissette]

Paul Spencer wrote:
> Sweet, thanks Daniel.  Can you confirm something for me please?  In the 
> sprintf, there is a zoneStr variable that appears to have no value and 
> perhaps shouldn't be there?  As far as I can see, there are only two 
> substitution points in the string and zoneStr shouldn't go in either one :)
> 

I think you're right, you should probably ignore zoneStr.

BTW, here is the same definition in PROJ.4 format, from MapServer's 
implementation of the WMS AUTO projections (function 
_msProcessAutoProjection() in mapfile.c):


       case 42001: /** WGS 84 / Auto UTM **/
         nZone = (int) floor( (dLon0 + 180.0) / 6.0 ) + 1;
         sprintf( szProjBuf,
                  "+proj=tmerc+lat_0=0+lon_0=%.16g+k=0.999600+x_0=500000"
                  "+y_0=%.16g+ellps=WGS84+datum=WGS84+units=%s",
                  -183.0 + nZone * 6.0,
                  (dLat0 >= 0.0) ? 0.0 : 10000000.0,
                  pszUnits);

Daniel
-- 
Daniel Morissette
http://www.mapgears.com/