I am interested in running a model that estimates the relationship between survival (0 or 1) and parameters of a non-linear growth model (A= asymptote, k = maximum growth rate, Ti = timing of maximum growth). I’ve specified a model below that gets close to what I am looking for (I think!). However, I’d like to get the estimate between survival and parameters at the population level with the intention of eventually asking how the relationship between growth parameters and survival might vary from year to year.
Thank you for time and help in advance,
#Prior for model prior_richards2 <- prior(normal(4, 1.0), nlpar = "A",resp='Weight') +prior(normal(5, 0.9), nlpar = "k",resp='Weight')+prior(normal(15, 2), nlpar = "Ti",resp='Weight')+prior(normal(2, 0.5), nlpar = "d",lb=1.1,ub=4,resp='Weight')+prior(normal(0.5,5), class = "Intercept",resp='Surv') #Non-linear growth model #Weight is repeatedly measured throughout a nestling life Richards_mod <- bf(Weight ~ (A*100)*(1+(d-1)*exp((-(k/100)*(Age-Ti))/(d^(d/(1-d)))))^(1/(1-d)),A+k+Ti~1+(1|p|Year),d~1,nl=T) #Survival model #Whether or not a nestling survives to fledge from the nest. 0 or 1 Surv_mod<- bf(Surv~(1|p|Year))+bernoulli(link = 'logit') SurvtoFledgeMod_AlphaUnfed_Year <- brm(Surv_mod+Richards_mod,data = KittChickAlphaUnfed, control = list(adapt_delta = 0.99,max_treedepth=15),cores=6,iter = 4000,chains = 6,thin = 10,prior=prior_richards2)