With great interest I've read the article of Mr.Bartmann about making sundials
using a spreadsheet program (reference in 'sundial links' WWW-page).
I encountered however 2 problems:
1. Incorrect formula for azimuth
Formula given in article: cos(A) = sin(d) - ( sin(lat) * sin(a) ) / (
cos(lat) * cos(a) )
which should be: cos(A) = ( sin(lat) * sin(a) - sin(d) ) / (
cos(lat) * cos(a) )
2. Using the ACOS function to return the azimuth angle is rather tricky,
because returned values are in the range from -pi till +pi.
Any comments/suggestions?
Hans Sassenburg
