phenolocrop (version 0.0.4)

doubleLogis: Double logistic function for the time-series data.

Description

Apply a time-series model, double logistic function , to the time-series trait data. This function was originally developed for the time-series data of rice CIg data. Fitting the time-series model is done by the "two-step procedure". For more information, see Taniguchi et al. (under review).

Usage

doubleLogis(
  dat,
  x,
  y,
  returnModels = FALSE,
  start = c(r2 = 0.05, r3 = 0.05, d2 = 40, d3 = 100),
  upper = c(r2 = 1, r3 = 1, d2 = 200, d3 = 200),
  lower = c(r2 = 0, r3 = 0, d2 = 0, d3 = 0)
)

Value

doubleLogis function returns the vector of estimated parameter values. If returnModels = TRUE, this function also returns the nls regression object.

Arguments

dat

data.frame including date and trait (e.g. canopy height).

x

Column name (character) for the date after sowing or planting.

y

Column name (character) for the trait.

returnModels

Logical value whether to return the time-series model object. Default is F.

start

Start values to estimate 'r2', 'r3', 'd2' and 'd3'. Default is 'c(r2 = 0.05, r3 = 0.05, d2 = 40, d3 = 100)'.

upper

Upper bounds to estimate 'r2', 'r3', 'd2' and 'd3'. Default is 'c(r2 = 1, r3 = 1, d2 = 200, d3 = 200)'.

lower

Lower bounds to estimate 'r2', 'r3', 'd2' and 'd3'. Default is 'c(r2 = 0, r3 = 0, d2 = 0, d3 = 0)'.

References

S. Taniguchi et al. (2025) Phenology analysis for trait prediction using UAVs in a MAGIC rice population with different transplanting protocols. Frontiers in Artificial Intelligence, 7, 1477637.

Examples

library(phenolocrop)
riceCIg_eg |>
   doubleLogis("x", "CIg")