# Combines prey preference and prey suitability Calculates a combined value for prey preference and prey suitability standardised to a value between 0 and 1. ```r calc_suit_vect(nsc, nfish, sc_Linf, prefs, tau) ``` ## Arguments - `nsc`: A numeric value representing the number of length classes in the model. - `nfish`: A numeric value representing the number of species in the model. - `sc_Linf`: A numeric vector of length `nsc` representing the length class at which each species reaches its asymptotic length. - `prefs`: An array of dimensions `nsc`, `nfish`, `nsc` and `nfish`. The first and second dimensions represent the prey whereas the the third and fourth dimensions represent the predator. - `tau`: A matrix of dimensions `nfish` and `nfish`. Row indices represent predators and column indices represent prey. A value of 1 at location `i`, `j` indicates prey `j` is eaten by predator `i`. ## Returns A list object of length `nfish`. Each element in the list is an array of dimensions `nsc`, `nsc` and `nfish` containing a value between 0 and 1 that represents prey preference and prey suitability for each species and length class. ## Details `tau` values are assigned to an array of dimensions `nsc`, `nfish`, `nsc` and `nfish` and multiplied by the array `prefs`. This creates an array of dimensions `nsc`, `nfish`, `nsc` and `nfish` indicating prey suitability. Prey suitability is then standardised to sum to 1 for each predator species in each length class. ## Examples ```r # 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_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 # Calculate predator-prey size preferences prefs <- calc_prefs(pred_mu=-2.25, pred_sigma=0.5, wgt, sc_Linf) # Calculate prey preference and prey suitability suit_M2 <- calc_suit_vect(nsc, nfish, sc_Linf, prefs, NS_tau) ``` ## References Hall, S. J., Collie, J. S., Duplisea, D. E., Jennings, S., Bravington, M., & Link, J. (2006). A length-based multispecies model for evaluating community responses to fishing. **Canadian Journal of Fisheries and Aquatic Sciences**, 63(6):1344-1359. ## See Also `calc_M2`.

calc_suit_vect function