daylength: daylength

In weather: Weather data manipulation

Description

Compute daylenght (photoperiod) at a latitude for a day of the year.

Usage

daylength(lat, doy)

Arguments

lat	latitude, in degrees. I.e. between -90.0 and 90.0
doy	Day of the year. Integer between 1 and 365

Value

double

References

William C. Forsythe, Edward J. Rykiel Jr., Randal S. Stahl, Hsin-i Wu, Robert M. Schoolfield, 1995. A model comparison for daylength as a function of latitude and day of the year. Ecological Modeling 80: 87-95.

Examples

daylength(52, 50)
daylength(5, 50)
daylength(55, 180)

p <- daylength(52, 1:365)
d <- dateFromDoy(1:365, 2001)
plot(d, p)

weather documentation built on May 2, 2019, 4:56 p.m.