PhenoKl: Phenology extraction in Inflection method (Zhang)

In phenofit: Extract Remote Sensing Vegetation Phenology

Phenology extraction in Inflection method (Zhang)

Description

Phenology extraction in Inflection method (Zhang)

Usage

PhenoKl(
  fFIT,
  t = NULL,
  analytical = FALSE,
  smoothed.spline = FALSE,
  IsPlot = TRUE,
  show.legend = TRUE,
  ...
)

Arguments

fFIT	object return by curvefit()
t	doy vector, corresponding doy of vegetation index.
analytical	If true, numDeriv package grad and hess will be used; if false, D1 and D2 will be used.
smoothed.spline	Whether apply smooth.spline first?
IsPlot	whether to plot?
show.legend	whether show figure lelend?
...	Other parameters will be ignored.

Value

A numeric vector, with the elements of: Greenup, Maturity, Senescence, Dormancy.

References

1. Zhang, X., Friedl, M. A., Schaaf, C. B., Strahler, A. H., Hodges, J. C. F. F., Gao, F., … Huete, A. (2003). Monitoring vegetation phenology using MODIS. Remote Sensing of Environment, 84(3), 471–475. \Sexpr[results=rd]{tools:::Rd_expr_doi("10.1016/S0034-4257(02)00135-9")}

Examples

# `doubleLog.Beck` simulate vegetation time-series
t    <- seq(1, 365, 8)
tout <- seq(1, 365, 1)
par  = c( mn  = 0.1 , mx  = 0.7 , sos = 50 , rsp = 0.1 , eos = 250, rau = 0.1)
y <- doubleLog.Beck(par, t)

methods <- c("AG", "Beck", "Elmore", "Gu", "Zhang") # "Klos" too slow
fit <- curvefit(y, t, tout, methods)
x <- fit$model$AG # one model

par(mfrow = c(2, 2))
PhenoTrs(x)
PhenoDeriv(x)
PhenoGu(x)
PhenoKl(x)

phenofit documentation built on June 8, 2025, 9:39 p.m.