selectivity: Selectivity functions

In inspktrgadget/gadgetSim: Create Gadget replicates for use in simulation studies

Description

Compute various selection probabilities on lengths. logistic_selectivity produces an asymptotic selection probability based on the logistic function. exponential_l50_selectivity is the same as logistic_selectivity. andersen_selectivity and gamma_selectivity both produce dome-shaped selectivity curves. Straightline is a simple line and constant is a simple line with no slope.

Usage

constant_selectivity(lengths, alpha)

straightline_selectivity(lengths, alpha, beta)

logistic_selectivity(lengths, alpha, l50, max_prop = 1)

exponential_l50_selectivity(lengths, alpha, l50, max_prop = 1)

andersen_fleet_selectivity(lengths, p0, p1, p2, p3)

gamma_selectivity(lengths, alpha, beta, gamma)

Arguments

alpha	Numeric. Steepness parameter for logistic and exponential_l50 functions, constant proportion for constant function and slope for straightline selectivity. Left to right scaling parameter for the gamma function
beta	Numeric. Intercept for the straightline function. Controls amount of doming on the gamma selectivity
l50	Numeric. Half-saturation parameter
max_prop	Numeric in [0,1]. This function controls the maximum level of selectivity in the logistic and exponential_l50 selectivity.
gamma	Numeric. Controls doming along with beta in gamma selectivity
length	Numeric. Length to evaluate selectivity on
p0-p3	Numeric. These arguments controls the shape of the Andersen selectivity function.

Value

Numeric vector the length of length ranging from 0 to max_prop

Examples

lengths <- 1:100
curve(logistic_selectivity(x, 0.2, 50, 0.5), 0, 100,
      ylim = c(0, 1), ylab = "Selectivity", xlab = "Length")
curve(exponential_l50_selectivity(x, 0.2, 50, 0.5), add = TRUE,
      col = "red", lty = 2)
curve(gamma_selectivity(x, 5, 0.7, 20), add = TRUE, col = 2)
curve(andersen_fleet_selectivity(x, 0.1, 0.1, 0.5, 50), add = TRUE, col = 3)
curve(constant_selectivity(x, 0.1), add = TRUE, col = 4)
curve(straightline_selectivity(x, 0.001, 0.1), add = TRUE, col = 5)
legend("topleft", legend = c("logistic", "exponential_l50", "gamma",
                              "andersen_fleet", "constant", "straightline"),
       col = c(1, "red", 2, 3, 4, 5), lty = c(1,2,1,1,1,1))

inspktrgadget/gadgetSim documentation built on May 10, 2019, 9:51 a.m.