simCAA {MSEtool} | R Documentation |
Simulate Catch-at-Age Data
Description
CAA generated with either a multinomial or logistic normal observation model from retained catch-at-age array
Usage
simCAA(nsim, yrs, n_age, Cret, CAA_ESS, CAA_nsamp)
Arguments
nsim |
Number of simulations |
yrs |
Number of years |
n_age |
Number of age classes |
Cret |
Retained Catch at age in numbers - array(sim, years, maxage+1) |
CAA_ESS |
CAA effective sample size. If greater than 1, then this is the multinomial distribution sample size. If less than 1, this is the coefficient of variation for the logistic normal distribution (see details). |
CAA_nsamp |
CAA sample size |
Details
The logistic normal generates the catch-at-age sample by first sampling once from a multivariate normal distribution with the mean vector equal to the logarithm of the proportions-at-age and the diagonal of the covariance matrix is the square of the product of the CV and the log proportions (all off-diagonals are zero). The sampled vector is then converted to proportions with the softmax function and expanded to numbers (CAA_nsamp). This method allows for simulating fractional values in the catch-at-age matrix.
Value
CAA array