XPost: alt.windows7.general, alt.comp.os.windows-10   
   From: address@is.invalid   
      
   Hello all,   
      
   I have a world map using the Mercator projection, and would like to plot   
   some stuff on it using Latitude and Longitude.   
      
   The problem is that I can't seem to get the formule I found to spit out the   
   correct value for Y.   
      
   -- The map :   
      
   https://upload.wikimedia.org/wikipedia/commons/thumb/7/73/Mercat   
   r_projection_Square.JPG/250px-Mercator_projection_Square.JPG   
      
   -- The formula :   
      
   Y = ln( tan(latitude) + sec(latitude) )   
      
   where "ln(...)" is log(...) / log(10)   
      
   ... at least, that is what I could google about it.   
      
   where "sec(...)" is 1/cos(...)   
      
   -- The test data :   
      
   New York : Latitude = 39 (Longitude = -77)   
      
   -- Applying the formula and checking the partial results :   
      
   RadLat = DegToRad(39) -> 0.680952380952381   
      
   Temp = tan(RadLat) + 1/cos(RadLat) -> 2.09728292053088   
      
   log(Temp)/log(10) -> 0.321657020135087   
      
   Multiplying half the maps height by the above tells me that New York is   
   located somewhere in Canada. :-(   
      
   Can anyone tell me what goes wrong here ?   
      
   Regards,   
   Rudy Wieser   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)