sunrise, sunset calculation

Are there any functions available to calculate sunrise and sunset times 
for given latitude,longitude and dates?
If not, I'll appreciatte any pointers to C code I could use/port.
Thanks,
Angel

Hello, I have R code for determining solar elevation for given lat,lon,time 
- they were translated from the Javascript on these pages.

  http://www.srrb.noaa.gov/highlights/sunrise/sunrise.html
  http://www.srrb.noaa.gov/highlights/sunrise/azel.html

I use them in a fairly specialized way, but I can dig it out and probably 
help you get started.

Cheers, Mike.




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Michael Sumner - PhD. candidate
Maths and Physics (ACE CRC & IASOS) and Zoology (AWRU)
University of Tasmania
Private Bag 77, Hobart, Tas 7001, Australia
Phone: 6226 1752


Overall, SAS is about 11 years behind R and S-Plus in statistical 
capabilities (last year it was
about 10 years behind) in my estimation.
    -- Frank Harrell (SAS User, 1969-1991)
       R-help (September 2003)