# calc_growth: Calculate growth In LeMaRns: Length-Based Multispecies Analysis by Numerical Simulation

## Description

Calculates the number of individuals of each species in each length class for the next time step.

## Usage

 `1` ```calc_growth(N, phi, nfish, nsc) ```

## Arguments

 `N` A matrix with dimensions `nsc` and `nfish` representing the number of individuals in each length class for the current time step. `phi` A matrix with dimensions `nsc` and `nfish` representing the proportion of individuals that leave each length class. `nfish` A numeric value representing the number of species in the model. `nsc` A numeric value representing the number of length classes in the model.

## Value

A matrix with dimensions `nsc` and `nfish` representing the number of individuals of each species in each length class for the next time step.

## Examples

 ``` 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31``` ```# Set up the inputs to the function - species-independent parameters nfish <- nrow(NS_par) nsc <- 32 maxsize <- max(NS_par\$Linf) * 1.01 # the biggest size is 1% bigger than the largest Linf l_bound <- seq(0, maxsize, maxsize/nsc); l_bound <- l_bound[-length(l_bound)] u_bound <- seq(maxsize/nsc, maxsize, maxsize/nsc) mid <- l_bound+(u_bound-l_bound)/2 # Set up the inputs to the function - species-specific parameters Linf <- NS_par\$Linf # the von-Bertalanffy asymptotic length of each species (cm). W_a <- NS_par\$W_a # length-weight conversion parameter. W_b <- NS_par\$W_b # length-weight conversion parameter. k <- NS_par\$k # the von-Bertalnaffy growth parameter. Lmat <- NS_par\$Lmat # the length at which 50\% of individuals are mature (cm). # Get phi_min tmp <- calc_phi(k, Linf, nsc, nfish, u_bound, l_bound, calc_phi_min=FALSE, phi_min=0.1) # fixed phi_min phi <- tmp\$phi phi_min <- tmp\$phi_min # Calculate growth increments tmp <- calc_ration_growthfac(k, Linf, nsc, nfish, l_bound, u_bound, mid, W_a, W_b, phi_min) sc_Linf <- tmp\$sc_Linf wgt <- tmp\$wgt # Get an initial population N0 <- get_N0(nsc, nfish, mid, wgt, sc_Linf, intercept=1e10, slope=-5) # Calculate growth growth <- calc_growth(N0, phi, nfish, nsc) ```

LeMaRns documentation built on Dec. 9, 2019, 5:09 p.m.