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Find Features on a Stream Network

Source: R/frs_feature_find.R
frs_feature_find.Rd

Locate features from a database table or sf object on the stream network. Produces a table with blue_line_key, downstream_route_measure, label, and source columns, suitable for frs_break_apply(), frs_feature_index(), or as a break source in frs_habitat().

Usage

frs_feature_find(
  conn,
  table,
  to = "working.features",
  points_table = NULL,
  points = NULL,
  where = NULL,
  col_blk = "blue_line_key",
  col_measure = "downstream_route_measure",
  col_id = NULL,
  label = NULL,
  label_col = NULL,
  label_map = NULL,
  overwrite = TRUE,
  append = FALSE
)

Arguments

conn

A DBI::DBIConnection object.

table

Character. Working streams table (for BLK scoping).

to

Character. Destination table name. Default "working.features".

points_table

Character or NULL. Schema-qualified table with network-referenced features.

points

An sf object or NULL. User-provided points to snap to the network via frs_point_snap().

where

Character or NULL. SQL predicate to filter points_table.

col_blk

Character. Column name for stream identifier in points_table. Default "blue_line_key".

col_measure

Character. Column name for route measure in points_table. Default "downstream_route_measure".

col_id

Character or NULL. Column name for feature ID. When provided, included in output for joining back to source.

label

Character or NULL. Static label for all features.

label_col

Character or NULL. Column name to read labels from.

label_map

Named character vector or NULL. Maps label_col values to output labels.

overwrite

Logical. Drop to before creating. Default TRUE.

append

Logical. INSERT INTO existing to table. Default FALSE.

Value

conn invisibly, for pipe chaining.

Details

Unlike frs_break_find() which is specific to gradient threshold detection, this function handles any point features on the network: crossings, fish observations, water quality stations, flow gauges, territory boundaries, etc.

See also

Other habitat: frs_aggregate(), frs_break(), frs_break_apply(), frs_break_find(), frs_break_validate(), frs_categorize(), frs_classify(), frs_cluster(), frs_col_generate(), frs_col_join(), frs_extract(), frs_feature_index(), frs_habitat(), frs_habitat_access(), frs_habitat_classify(), frs_habitat_overlay(), frs_habitat_partition(), frs_habitat_predicates(), frs_habitat_species(), frs_network_segment()

Examples

if (FALSE) { # \dontrun{
conn <- frs_db_conn()

# Crossings with severity labels
frs_feature_find(conn, "working.streams",
  points_table = "working.crossings",
  col_id = "aggregated_crossings_id",
  label_col = "barrier_status",
  label_map = c("BARRIER" = "blocked", "POTENTIAL" = "potential"),
  to = "working.features_crossings")

# Fish observations
frs_feature_find(conn, "working.streams",
  points_table = "bcfishobs.fiss_fish_obsrvtn_events_vw",
  col_id = "fish_observation_point_id",
  label_col = "species_code",
  to = "working.features_fish_obs")

# Use as break source in habitat pipeline
frs_habitat(conn, "BULK", break_sources = list(
  list(table = "working.features_crossings",
       label_col = "label")))

DBI::dbDisconnect(conn)
} # }