irg (version 0.1.6)

filter_roll: 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.

Value

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

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.

See Also

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

Examples

# NOT RUN {
# 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')
# }