disambiguate_flowline_indexes {nhdplusTools}

Disambiguate Flowline Indexes

Description

Given a set of flowline indexes and numeric or ascii criteria, return closest match. If numeric criteria are used, the minimum difference in the numeric attribute is used for disambiguation. If ascii criteria are used, the adist function is used with the following algorithm: '1 - adist_score / max_string_length'. Comparisons ignore case.

Usage

disambiguate_flowline_indexes(indexes, flowpath, hydro_location)

Arguments

indexes

data.frame as output from get_flowline_index with more than one hydrologic location per indexed point.

flowpath

data.frame with two columns. The first should join to the COMID field of the indexes and the second should be the numeric or ascii metric such as drainage area or GNIS Name. Names of this data.frame are not used.

hydro_location

data.frame with two columns. The first should join to the id field of the indexes and the second should be the numeric or ascii metric such as drainage area or GNIS Name.. Names of this data,frame are not used.

Value

data.frame indexes deduplicated according to the minimum difference between the values in the metric columns. If two or more result in the same "minimum" value, duplicates will be returned.

Examples

source(system.file("extdata", "sample_flines.R", package = "nhdplusTools"))

hydro_location <- sf::st_sf(id = c(1, 2, 3),
                            geom = sf::st_sfc(list(sf::st_point(c(-76.86934, 39.49328)),
                                                   sf::st_point(c(-76.91711, 39.40884)),
                                                   sf::st_point(c(-76.88081, 39.36354))),
                                              crs = 4326),
                            totda = c(23.6, 7.3, 427.9),
                            nameid = c("Patapsco", "", "Falls Run River"))

flowpath <- dplyr::select(sample_flines,
                          comid = COMID,
                          totda = TotDASqKM,
                          nameid = GNIS_NAME,
                          REACHCODE,
                          ToMeas,
                          FromMeas)

indexes <- get_flowline_index(flowpath,
                              hydro_location,
                              search_radius = 0.2,
                              max_matches = 10)

disambiguate_flowline_indexes(indexes,
                              dplyr::select(flowpath, comid, totda),
                              dplyr::select(hydro_location, id, totda))

result <- disambiguate_flowline_indexes(indexes,
                                        dplyr::select(flowpath, comid, nameid),
                                        dplyr::select(hydro_location, id, nameid))

result[result$id == 1, ]

result[result$id == 2, ]

result[result$id == 3, ]