Applies a topological sort and calculates stream level. Algorithm: Terminal level paths are assigned level 1 (see note 1). Paths that terminate at a level 1 are assigned level 2. This pattern is repeated until no paths remain.
If a TRUE/FALSE coastal attribute is included, coastal terminal paths begin at 1 and internal terminal paths begin at 4 as is implemented by the NHD stream leveling rules.
data.frame with levelpathi, dnlevelpat, and optionally a coastal flag. If no coastal flag is included, all terminal paths are assumed to be coastal.
numeric stream order in same order as input
source(system.file("extdata", "walker_data.R", package = "nhdplusTools")) test_flowline <- data.frame( levelpathi = walker_flowline$LevelPathI, dnlevelpat = walker_flowline$DnLevelPat) test_flowline$dnlevelpat <- 0 (level <- get_streamlevel(test_flowline)) walker_flowline$level <- level plot(sf::st_geometry(walker_flowline), lwd = walker_flowline$level, col = "blue") test_flowline$coastal <- rep(FALSE, nrow(test_flowline)) (level <- get_streamlevel(test_flowline)) test_flowline$coastal[!test_flowline$dnlevelpat %in% test_flowline$levelpathi] <- TRUE (level <- get_streamlevel(test_flowline))
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