STLperArea: Seasonal Decomposition per Area

In ndvits: NDVI Time series extraction and analysis

Description

Make a Seasonal Decomposition of Time Series by Loess per group of pixels

Usage

STLperArea(TS, area, outfile = FALSE, Ystart, period = 36, fct = "mean", SGfilter = TRUE, nSG = "5,5", DSG = 0)

Arguments

TS	matrix or data.frame containing the time series (one row per time series).
area	factor which group pixels of the same area together (applying fct per area)
outfile	name of the file where the decomposition is saved (extension ".pdf"). If outfile=FALSE, the graphs are not saved but displayed in the R graphic console. By default, outfile = FALSE.
Ystart	starting year of the analysis (in four-digit format).
period	number of observations per year. For VGT's dataset : period=36, GIMMS's dataset: period=24.
fct	function to be applied to group points from the same area : "mean", "max" or "min". By default fct="mean".
SGfilter	logical value indicating the application of Savitzky-Golay (SG) filter on time series By default SGfilter=TRUE
nSG	parameters of the windows of the SG filter. By default nSG="5,5" (windows 5,5).
DSG	parameters of the degree polynome of the SG filter. By default, DSG=0.

Value

The output of STLperArea is the time series computed (mean/max of the time series grouped by area and with/without Savitzky-Golay filter).

Author(s)

Romain Frelat and Bruno Gerard

See Also

TimeSeriesAnalysis,BfastDec

Examples

#loading the data
data(SLPSAs_full)

#formating the time series
ts = normNDVI(SLPSAs_full$full, SLPSAs_full$maxNDVI)

#STLperArea

signal=STLperArea(ts, area = SLPSAs_full$full$name, 
    Ystart = SLPSAs_full$Ystart, period = SLPSAs_full$period)

ndvits documentation built on May 2, 2019, 4:47 p.m.