model - 无法评估 N 的子集表达式

Question

我一直在尝试运行单季单物种入住，但 R 不断给出错误：

Cannot evaluate subset expression for N

我已附上 JAGS 脚本。

model{
  # Likelihood
  for(i in 1:nSites){
    # biological model
    logit(psi[i]) <- b0 + bHumans * hums[i] + 
        bElevation * ele[i] + bDD * dd[i] + bRuggedness * rugged[i] + bLivestock * livstck[i] + bVillage_dist * village[i]
    z[i] ~ dbern(psi[i])
    # observation model
    y[i] ~ dbin(p * z[i], n[i])
  }

  # Priors
  psi0 ~ dbeta(1, 1)
  b0 <- logit(psi0)
  bHumans ~ dunif(-5, 5)    # humans
  bElevation ~ dunif(-5, 5)   # elevation
  bDD ~ dunif(-5, 5)  # dd
  bRuggedness ~ dunif(-5,5) # rugg
  bLivestock ~ dunif(-5,5) #livestock
  bVillage_dist ~ dunif(-5,5) # village
  p ~ dbeta(1, 1)
  
  # Derived variable
  N <- sum(z)
}

标签： modelcompilationsubsetjags