[mapserver-users] More about SCALE calculations

[Lars V. Nielsen]

Hi List,

Just wanted to share my latest findings on the SCALE issue.
After testing various combinations of extent (zoom), width and scales I've
discovered a constant !

It seems these formulas will work (scale_number is > 1, i.e. scale =
1:scale_number) :

Constant = (field width in meters) / ( (scale_number) * (pixel width) ) =
0.000352777... = 1 / 2834.6472..
I.e.
Scale_number = (field width in meters) / ( (pixel width) * 0.000352777.. )

It's workable for now, but I'd still like to know what this constant
represents (if anything) ??
'cause I'm not sure whether more parameters should go into the equations,
e.g. (server) screen size and resolution ???

Best regards / Med venlig hilsen
Lars V. Nielsen
--------------------------------------------------------
Hvenegaard & Meklenborg, Odense
Denmark
http://www.hvm.dk