As several dialists have asked me to give my report also in PDF-format I have included a PDF-version of the report in
ftp://ftp.cc.tut.fi/pub/math/ruohonen/Raportit/PRep9/ To read this version you'll need to install Adobe's Acrobat Reader, freely downloadable from http://www.adobe.com/prodindex/acrobat/ Keijo Ruohonen > > Hello, Alberto! > >Yes, it does make a fine math problem, one you have to solve numerically >using a computer. You will indeed need two spindle-shaped gnomons, one >for spring and one for autumn. Mathematically speaking, the gnomons are >however infinite surfaces, that is, they flare to infinity near the times >of solstices! So, a totally accurate solution working throughout the >year does not exist. Various approximative solutions abound, of course. > >I once wrote a report which contains all the math and lots of pictures: > > K. Ruohonen: Designing Sundials by Matlab and Maple. Tampere University > of Technology. Department of Information Technology. Mathematics > Software Report 9 (1995) > >It is also available in the net (in Postscript): > > ftp://ftp.cc.tut.fi/pub/math/ruohonen/Raportit/PRep9/ > >(For those interested, the math is here formulated using matrices >and vector calculus.) In principle, the sundial face could be arbitrarily >oriented but the gnomon surfaces tend then to be very complicated. Simple >things like time shifts are easily incorporated. > %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%NULLIUS%IN%VERBA% Keijo Ruohonen Tampere University of Technology [EMAIL PROTECTED] Department of Mathematics Voice (+358) (3) 3652420 http://www.cc.tut.fi/ Tampere, FINLAND Fax (+358) (3) 3653549 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
