photoperiod {meteor}R Documentation

photoperiod

Description

Compute photoperiod (daylength, sunshine duration) at a given latitude and day of the year.

Usage

photoperiod(doy, latitude)

Arguments

doy

integer. Day of the year. Integer between 1 and 365

latitude

numeric. Latitude, in degrees, should be between -90 and 90

Value

double. Photoperiod in hours

References

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.

Examples

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

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

[Package meteor version 0.3-4 Index]