photoperiod {meteor} | R Documentation |
Compute photoperiod (daylength, sunshine duration) at a given latitude and day of the year.
photoperiod(doy, latitude)
doy |
integer. Day of the year. Integer between 1 and 365 |
latitude |
numeric. Latitude, in degrees, should be between -90 and 90 |
double. Photoperiod in hours
Forsythe, W.C., E.J. Rykiel Jr., R.S. Stahl, H. Wu, R.M. Schoolfield, 1995. A model comparison for photoperiod as a function of latitude and day of the year. Ecological Modeling 80: 87-95.
photoperiod(50, 52) photoperiod(50, 5) photoperiod(180, 55) p <- photoperiod(1:365, 52) d <- dateFromDoy(1:365, 2001) plot(d, p)