grow: Project Growth

In TobieSurette/gulf.data: Southern Gulf of St Lawrence Data Access

Project Growth

Description

Functions to estimate the deterministic or probabilistic future size of an organism.

Usage

grow(x, ...)

Arguments

x	Specimen size or length-frequency. Fish size units are usually in centimeters while those of crustaceans are generally in millimeters. x may be a frequency table.
x0	Numeric value(s) at which probabilistic growth frequencies are to be estimated. Note that using x0 signals the function to use a probabilistic projection of growth, rather than a deterministic one. See examples.
n	Numeric value(s) specifying the number of iterations (e.g. number of moults) to apply the growth functions. Non-integer values are allowed.

Examples

# Deterministic growth:
grow(60, species = "lobster")         # Post-moult size for a 60mm CL lobster.
grow(30:100, species = "lobster")     # Post-moult size for a range of lobster CL sizes.
grow(30:100, species = "snow crab")   # Post-moult size for a range of lobster CW sizes.

# Probabilistic growth:
x0 <- seq(60, 100, len = 1000)        # Post-moult size values at which we wish to know the probability density.
y0 <- grow(60, x0 = x0, species = "snow crab") # Estimate post-moult size probability densities for a single 60mm crab.
plot(x0, y0, type = "l", xlab = "Carapace width (mm)", ylab = "Probability density")

# Probabilistic growth for multiple observations:
x0 <- seq(60, 100, len = 1000)        # Post-moult size values at which we wish to know the probability density.
y0 <- grow(c(60, 60, 70, 75), x0 = x0, species = "snow crab") # Estimate post-moult size probability densities for a single 60mm crab.
plot(x0, y0, type = "l", xlab = "Carapace width (mm)", ylab = "Probability density")

# Probabilistic growth for large sample:
x <- read.scsbio(2020, category = "MI") # Immature males.
x0 <- seq(0, 140, len = 1000)
grow(x$carapace.width, species = "snow crab") # Deterministic.
plot(x0, grow(x$carapace.width, x0, species = "snow crab"), 
     type = "l", xlab = "Carapace width (mm)", ylab = "Frequency")
     
# Control number of moults:
grow(60, n = 0, species = "snow crab") # No moult.
grow(60, n = 1, species = "snow crab") # One moult (default).
grow(60, n = 2, species = "snow crab") # Two moults.
grow(c(60, 70, 80), n = c(0,1,2), species = "snow crab") # Three sizes with 0, 1 and 2 moults.

TobieSurette/gulf.data documentation built on Jan. 19, 2025, 7:50 p.m.