filter_roll: Filter with rolling median

In robitalec/irg: Instantaneous Rate of Green Up

Filter with rolling median

Description

Using a rolling median, filter the NDVI time series for each id.

Usage

filter_roll(DT, window = 3L, id = "id", method = "median")

Arguments

DT	data.table of NDVI time series
window	window size. default is 3.
id	id column. default is 'id'. See details.
method	median. no other options yet. let me know if you are looking for something else.

Details

The id argument is used to split between sampling units. This may be a point id, polygon id, pixel id, etc. depending on your analysis.

Value

filtered data.table with appended 'rolled' column of each id's rolling median, filtered NDVI time series.

See Also

Other filter: filter_ndvi(), filter_qa(), filter_top(), filter_winter()

Examples

# Load data.table
library(data.table)

# Read example data
ndvi <- fread(system.file("extdata", "sampled-ndvi-MODIS-MOD13Q1.csv", package = "irg"))

filter_qa(ndvi, ndvi = 'NDVI', qa = 'SummaryQA', good = c(0, 1))
filter_winter(ndvi, probs = 0.025, limits = c(60L, 300L), doy = 'DayOfYear', id = 'id')
filter_roll(ndvi, window = 3L, id = 'id')

robitalec/irg documentation built on Sept. 19, 2023, 9:33 p.m.