phenofit (version 0.3.2)

PhenoExtractMeth: Phenology Extraction methods

Description

• PhenoTrs Threshold method

• PhenoDeriv Derivative method

• PhenoGu Gu method

• PhenoKl Inflection method

Usage

PhenoTrs(
  fFIT,
  t = NULL,
  approach = c("White", "Trs"),
  trs = 0.5,
  asymmetric = TRUE,
  IsPlot = TRUE,
  ...
)
PhenoDeriv(
  fFIT,
  t = NULL,
  analytical = TRUE,
  smoothed.spline = FALSE,
  IsPlot = TRUE,
  show.lgd = TRUE,
  ...
)
PhenoGu(
  fFIT,
  t = NULL,
  analytical = TRUE,
  smoothed.spline = FALSE,
  IsPlot = TRUE,
  ...
)
PhenoKl(
  fFIT,
  t = NULL,
  analytical = TRUE,
  smoothed.spline = FALSE,
  IsPlot = TRUE,
  show.lgd = TRUE,
  ...
)

Arguments

fFIT

fFIT object returned by optim_pheno().

t

date or doy vector, with the same length as ypred. This parameter is for the Julia version curvefits.

approach

to be used to calculate phenology metrics. 'White' (White et al. 1997) or 'Trs' for simple threshold.

trs

threshold to be used for approach "Trs", in (0, 1).

asymmetric

If true, background value in spring season and autumn season is regarded as different.

IsPlot

whether to plot?

...

other parameters to PhenoPlot

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?

show.lgd

whether show figure lelend?

Examples

library(phenofit)
# simulate vegetation time-series
fFUN = doubleLog.Beck
par  = c( mn  = 0.1 , mx  = 0.7 , sos = 50 , rsp = 0.1 , eos = 250, rau = 0.1)

t    <- seq(1, 365, 8)
tout <- seq(1, 365, 1)
y <- fFUN(par, t)

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

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