GRTPsi_models: Hydro-Thermal-time models based on the germination rate

In OnofriAndreaPG/drcSeedGerm: Utilities for Data Analyses in Seed Germination/Emergence Assays

Hydro-Thermal-time models based on the germination rate

Description

These models are used to describe the germination rate of a seed, depending on the environmental temperature and water potential.

Usage

GRTPsi.M()
GRTPsi.M.fun(Temp, Psi, k, Tb, ThetaHT, Psib)
GRTPsi.BS()
GRTPsi.BS.fun(Temp, Psi, k, Tb, To, ThetaHT, Psib)

Arguments

Temp	Temperature variable
Psi	Water potential variable
Psib	Base water potential variable
k	regression parameter
Tb	base temperature
To	optimal temperature
ThetaHT	Hydro-thermal-time parameter

Details

The 'GRT.M.fun()' is a generic R function, while the GRT.M() function is meant to be used with the 'drm()' function, within the 'drc' package.

Value

The 'GRT.M.fun()' functions returns a vector of responses, for given values of temperature, Tc, Tb and ThetaH. The GRT.M() function returns a list containing the nonlinear function, the self starter function, the parameter names and other items which are internally used by the 'drm()' function.

Author(s)

Andrea Onofri

References

https://www.statforbiology.com/2023/stat_drcte_12-htt2step/

Examples

library(drcte)
Tval <- c(2, 5, 10, 15, 20, 25, 30, 35, 40)
GR <- c(0, 0, 0.209, 0.435, 0.759, 0.821, 0.417, 0.145, 0)
modM <- drm(GR ~ Tval, fct = GRT.M())
plot(modM, log="", xlim = c(0, 40), ylim=c(0,1.2),
     legendPos = c(5, 1.0), xlab = "Temperature (°C)")

OnofriAndreaPG/drcSeedGerm documentation built on Jan. 13, 2025, 5:53 a.m.