Effort trend for one fleet — effort

Describes the shape of a fleet's nominal effort over time. "fudc" is the up-down-constant shape of FLRef::fudc(): effort starts at e0 in the first year, rises linearly to fhi x fref by the first break, moves linearly to flo x fref by the second break and stays there. "values" takes a user-supplied vector, one value per year.

Usage

effort_trend(
  type = c("fudc", "values"),
  e0 = 0.05,
  fhi = 1,
  flo = 0.8,
  fref = 1,
  breaks = c(0.5, 0.75),
  values = NULL
)

Arguments

type: "fudc" or "values".
e0: effort in the first year (relative units; near-unfished start).
fhi, flo, fref: levels for "fudc" (relative units).
breaks: two proportions of the time series (0-1) where the trend reaches fhi and then flo.
values: numeric vector of relative effort, one per year ("values").

Value

a list of class floss_trend.

Examples

effort_trend(fhi = 1, flo = 0.8, breaks = c(0.4, 0.6))
#> $type
#> [1] "fudc"
#> 
#> $e0
#> [1] 0.05
#> 
#> $fhi
#> [1] 1
#> 
#> $flo
#> [1] 0.8
#> 
#> $fref
#> [1] 1
#> 
#> $breaks
#> [1] 0.4 0.6
#> 
#> attr(,"class")
#> [1] "floss_trend"