non-dendritic.R
In hydroloom: Utilities to Weave Hydrologic Fabrics

## ----setup, include = FALSE---------------------------------------------------
library(hydroloom)
library(dplyr)

local <- (Sys.getenv("BUILD_VIGNETTES") == "TRUE")

knitr::opts_chunk$set(
  collapse = TRUE,
  warning = FALSE,
  comment = "#>",
  fig.width=6,
  fig.height=6,
  fig.align = "center",
  eval=local
)

oldoption <- options(scipen = 9999)


## -----------------------------------------------------------------------------

x <- sf::read_sf(system.file("extdata/new_hope.gpkg", 
                             package = "hydroloom"))

# First we select only an id, a name, and a feature type.
flow_net <- x |>
  select(COMID, GNIS_ID, FTYPE) |>
  sf::st_transform(5070)

# Now we convert the geometric network to an attribute topology
# and convert that to a node topology and join our attributes back
flow_net <- flow_net |>
  make_attribute_topology(min_distance = 5) |>
  hydroloom::make_node_topology(add_div = TRUE) |>
  left_join(sf::st_drop_geometry(flow_net), by = "COMID")

# We only have one outlet so it doesn't matter if it is coastal
# or inland but we have to provide it.
outlets <- filter(flow_net, !tonode %in% fromnode)

# We have these feature types. A larger dataset might include 
# things like canals which would not be considered  "major"
unique(flow_net$FTYPE)

# now we run the add_divergence, add_toids, and add_streamorder
flow_net <- add_divergence(flow_net, 
                           coastal_outlet_ids = c(), 
                           inland_outlet_ids = outlets$COMID, 
                           name_attr = "GNIS_ID", 
                           type_attr = "FTYPE", 
                           major_types = unique(flow_net$FTYPE)) |>
  add_toids() |>
  add_streamorder() |>
  add_return_divergence()

# Make sure we reproduce what came from our source NHDPlus data.
sum(flow_net$divergence == 2)
sum(x$Divergence == 2)
all(flow_net$divergence == x$Divergence)
sum(flow_net$return_divergence == x$RtnDiv)

names(flow_net)