filter_roll: Filter with rolling median
In irg: Instantaneous Rate of Green Up

Description Usage Arguments Details Value See Also Examples

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

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

`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.

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.

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

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

# 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')