forcingUnits: Forcing units

In baeyc/dormancy:

Description

Compute forcing units accumulated by a plant, according to a beta-shaped function.

Usage

forcingUnits(
  temp.data,
  var.names = list(temp = "temp", date = "date", duration = "duration"),
  temp.min = 5,
  temp.max = 30,
  a,
  b
)

Arguments

temp.data	a data frame with the dates and temperatures to accumulate
var.names	the name of the temperature and date variables, in the format list(temp="temp.name",date="date.name",duration="duration.name")
temp.min	the threshold above which the plant is accumulating chilling units
temp.max	the threshold below which the plant is accumulating chilling units
a	the temperature at which the plant accumulates half the maximum of forcing units
b	the rate of forcing units accumulation

Details

The accumulation of forcing units is expressed through a logistic curve with parameters a and b:

fu(t) = \frac{1}{1 + \exp(-(t-a)/b)}

if temp.min ≤q t ≤q temp.max, and 0 otherwise, and where a is the temperature at which the plant accumulates half the maximum of forcing units and b is the rate of accumulation

Value

a vector with the forcing units corresponding to each input temperature

baeyc/dormancy documentation built on May 7, 2021, 1:09 a.m.