[R-sig-Geo] Plot the location of a break point identified by the bfastlite function

[Nikolaos Tziokas]

I am using the bfastlite funtion from the bfast package for time-series
analysis of nighttime light (NTL) imagery. I have monthly data from April
2013 to December 2022 (129 monthly images). Using the code below, the
bfastlite found 2 breaks in the time-series data:

library(bfast)
library(terra)

wd <- "path/"

l <- list.files(paste0(wd), pattern = '.tif$',
                all.files = TRUE, full.names = FALSE)


rr <- lapply(paste0(wd, l), rast)
standard <- rr[[1]]

rs <- list(standard)
for (i in 2:length(rr)) {
  rr[[i]] <- terra::crop(rr[[i]], standard, extend = TRUE)
}

s <- rast(rr)

m <- terra::as.matrix(s)
m <- m[!rowSums(is.na(m)), ]

# convert the matrix to timeseries matrix
tm <- ts(data = m, start = c(2013, 4), end = c(2022, 12), frequency = 12,
class = "ts")

bf <- bfastlite(
  tm,
  formula = response ~ harmon,
  order = 3,
  breaks = "all",
  lag = 17,
  slag = 7,
  na.action = na.omit,
  stl = "none",
  decomp = c("stl", "stlplus"),
  sbins = 1,
  h = .25,
  level = 0.5,
  type = c("OLS-MOSUM", "RE"),
  plot = TRUE,
  hpc = "foreach"
)

bf
plot(bf)


How can I plot the location (i.e., pixels) of the breakpoints? You can
download the dataset from my GoogleDrive
<https://drive.google.com/drive/folders/1UloTKYHa7I3Wi_2pt3n3xbZ6vFvVz3_Y?usp=sharing>.
The entire code runs in less than 10 seconds.

-- 
Tziokas Nikolaos
Cartographer

Tel:(+44)07561120302
LinkedIn <http://linkedin.com/in/nikolaos-tziokas-896081130>

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