amadeus (version 1.2.2)

sum_edc: Calculate Sum of Exponentially Decaying Contributions (SEDC) covariates

Description

Calculate Sum of Exponentially Decaying Contributions (SEDC) covariates

Usage

sum_edc(
  from = NULL,
  locs = NULL,
  locs_id = NULL,
  sedc_bandwidth = NULL,
  target_fields = NULL,
  geom = FALSE
)

Value

a data.frame (tibble) or SpatVector object with input field names with a suffix "_sedc" where the sums of EDC are stored. Additional attributes are attached for the EDC information.

• `attr(result, "sedc_bandwidth")``: the bandwidth where concentration reduces to approximately five percent

• `attr(result, "sedc_threshold")``: the threshold distance at which emission source points are excluded beyond that

Arguments

from

SpatVector(1). Point locations which contain point-source covariate data.

locs

sf/SpatVector(1). Locations where the sum of exponentially decaying contributions are calculated.

locs_id

character(1). Name of the unique id field in point_to.

sedc_bandwidth

numeric(1). Distance at which the source concentration is reduced to exp(-3) (approximately -95 %)

target_fields

character(varying). Field names in characters.

geom

FALSE/"sf"/"terra".. Should the function return with geometry? Default is FALSE, options with geometry are "sf" or "terra". The coordinate reference system of the sf or SpatVector is that of from.

Author

Insang Song

References

messier2012integratingamadeus

web_sedctutorial_packageamadeus

Examples

set.seed(101)
ncpath <- system.file("gpkg/nc.gpkg", package = "sf")
nc <- terra::vect(ncpath)
nc <- terra::project(nc, "EPSG:5070")
pnt_locs <- terra::centroids(nc, inside = TRUE)
pnt_locs <- pnt_locs[, "NAME"]
pnt_from <- terra::spatSample(nc, 10L)
pnt_from$pid <- seq(1, 10)
pnt_from <- pnt_from[, "pid"]
pnt_from$val1 <- rgamma(10L, 1, 0.05)
pnt_from$val2 <- rgamma(10L, 2, 1)

vals <- c("val1", "val2")
sum_edc(pnt_locs, pnt_from, "NAME", 1e4, vals)