Place site visits on link's segments, with access and habitat for every species

scripts/0290's placement, on one schema for every species at once. A visit takes the segment of its blue line whose downstream end lies within [measure - 1, measure + start_window_m], the lowest such start if there are several (link breaks streams at observations, and an FDIS site's point sits at or a few metres below the record's). Only when no segment starts in that window does it take the segment containing its point; adjacent segments overlap by up to a few millimetres at breaks, so there the segment with the greatest downstream measure wins and id_segment breaks any tie. An overlap longer than overlap_max_m anywhere a visit's point falls stops the run.

Usage

knw_link_place(conn, visits, schema, start_window_m = 5, overlap_max_m = 0.01)

Arguments

conn

a DBI connection to a database holding schema.

visits

data.frame with site_visit, watershed_group_code, blue_line_key and downstream_route_measure.

schema

character(1) link persist schema, e.g. "fresh_default".

start_window_m

numeric(1) metres above the visit within which a segment start is taken as the visit's segment.

overlap_max_m

numeric(1) the largest segment overlap tolerated.

Value

A list: placed, one row per placed visit (site_visit, id_segment, segment_start_offset_m, the segment attributes, elevation, access_<sp> columns, <sp>_<flag> and <sp>_<flag>_stored columns); species_access, the species with an access_<sp> column; species_habitat, the species with a habitat table; overlap, a one-row data.frame with the number of visits whose point lies in two segments and the largest overlap found.

Details

Each placed visit carries the segment's attributes, its access_<sp> from streams_access for every species the schema models, and for every species with a habitat table its accessible, spawning, rearing, lake_rearing and wetland_rearing, re-gated on access_<sp> > 0 (link#349: the two columns disagree, and streams_access is the gate). The stored habitat flag is kept beside the re-gated one as <sp>_<flag>_stored.

Examples

if (FALSE) { # \dontrun{
conn <- DBI::dbConnect(RPostgres::Postgres())
v <- data.frame(site_visit = "x", watershed_group_code = "BULK",
                blue_line_key = 360886335, downstream_route_measure = 1520.4)
knw_link_place(conn, v, "fresh_default")$placed
} # }