Phenology extraction in Threshold method (TRS)

Phenology extraction in Threshold method (TRS)

PhenoTrs(
  x,
  t = NULL,
  approach = c("White", "Trs"),
  trs = 0.5,
  asymmetric = TRUE,
  IsPlot = TRUE,
  ...
)

# S3 method for class 'fFIT'
PhenoTrs(x, t = NULL, ...)

# Default S3 method
PhenoTrs(
  x,
  t = NULL,
  approach = c("White", "Trs"),
  trs = 0.5,
  asymmetric = TRUE,
  IsPlot = TRUE,
  ...
)

Arguments

x

numeric vector, or fFIT object returned by curvefit().

t

doy vector, corresponding doy of vegetation index.

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

See also

PhenoDeriv(), PhenoGu(), PhenoKl()

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)
#> sos eos 
#>  50 250 
PhenoDeriv(x)
#> sos pos eos 
#>  47 150 253 
PhenoGu(x)
#>  UD  SD  DD  RD 
#>  26  73 227 275 
PhenoKl(x)

#>    Greenup   Maturity Senescence   Dormancy 
#>         16         82        218        284