Add swept-area estimates to a datras_raw object

Compute haul-level swept-area estimates for a datras_raw / DATRASraw object using one of the supported methods.

Usage

add_swept_area(
  x,
  method = "simple",
  min_speed = 1,
  min_dist = 0,
  max_dist_dev = 0.2,
  impute_missing = FALSE,
  width = "WingSpread",
  verbose = TRUE,
  full_report = FALSE
)

Arguments

x

A datras_raw object.

method

Character string specifying the method used to calculate swept area. Must be either "simple" (default) or "fishglob".

min_speed

Minimum plausible ground speed. Values below this threshold are treated as missing. Only used when method = "simple". Defaults to 1.

min_dist

Minimum plausible towing distance. Values below this threshold are treated as missing. Only used when method = "simple". Defaults to 0.

max_dist_dev

Maximum relative deviation allowed between recorded distance and distance reconstructed from HaulDur and GroundSpeed. Distances with larger deviations are treated as missing. Only used when method = "simple". Defaults to 0.2.

impute_missing

Logical. Only used when method = "simple". Defaults to FALSE.

width

Character string specifying which spread column to use as trawl width. Must be either "WingSpread" (default) or "DoorSpread". Only used when method = "simple"; ignored for method = "fishglob".

verbose

Logical. If TRUE (default) and method = "simple", print a summary of swept-area missingness and imputation by survey and gear.

full_report

Logical. If TRUE, the printed and attached summary also includes per-column missingness counts (na_DoorSpread, na_WingSpread, na_Distance, na_HaulDur, na_GroundSpeed) for the original input columns. Only used when method = "simple". Defaults to FALSE.

Value

A datras_raw object with swept-area estimates added.

Details

This function is a wrapper around an internal simple swept-area function and add_swept_area_fishglob(). It allows users to choose between a simple rule-based approach and the FishGlob workflow.

If method = "simple", swept area is calculated using a simple rule-based approach that applies basic plausibility filters, gear-specific median imputations, and a direct distance-times-width calculation. A per-haul logical column SweptArea_imputed is added to HH, and a survey-by-gear summary of missingness and imputation is attached as attr(x, "swept_area_summary") (and printed when verbose = TRUE).

If method = "fishglob", swept area is calculated using add_swept_area_fishglob(), which follows the FishGlob workflow based on survey-specific spread models and hierarchical fallback rules.

See also

add_swept_area_fishglob()

Examples

if (FALSE) { # \dontrun{
## Simple swept-area estimation
x <- add_swept_area(x)

## FishGlob workflow
x <- add_swept_area(x, method = "fishglob")

## Simple method with stricter filters
x <- add_swept_area(x, method = "simple", min_speed = 2,
                    max_dist_dev = 0.1)
} # }