Day of year when increasing from minval to
maxval begins.
doy.max
Day of year when maxval is reached.
doy.min
Day of year when minval is reached again.
shape.incr
Shape parameter of the increasing phase.
shape.decr
Shape parameter of the decreasing phase.
maxdoy
Length of the year, 366 for leap years, 365 for normal years.
References
Jansson, P.-E. & Karlberg, L. (2004): "Coupled heat and mass transfer model for
soil-plant-atmosphere systems."
Royal Institute of Technolgy, Dept of Civil and Environmental Engineering Stockholm