Hi all,

I am comparing models with the loo_compare function where I’ve used a kfold criterium.

Can anyone suggest why I am getting the following NaN elpd_diff and se_diff output.

```
elpd_diff se_diff
```

sprfit2t 0.0 0.0

sprcrop_k30t -10.9 4.9

crop_spr3t NaN NA

crop_spr4t NaN NA

```
The two models with the NaN issue are as follows:
bf3<-bf(Total ~ b0 +
b1 * (dist_3) +
b2 * lambda * log1p_exp((dist_3 - omega)/lambda) +
b3 * inv_logit((dist_3 - omega)/lambda),
b0 + b1 + b2 + b3 + lambda + omega ~ 1,
nl = TRUE)
crop_spr3<-brm(bf3, data = sprcrop_1.df, prior = bprior3,iter=26000,family="hurdle_gamma", control = list(adapt_delta=0.9999, max_treedepth = 14), core=6)
and
bf4<-bf(Total ~ b0 +
b1 * (dist_3) +
b2 * lambda * log1p_exp((dist_3)/lambda) +
b3 * inv_logit((dist_3)/lambda),
b0 + b1 + b2 + b3 + lambda ~ 1,
nl = TRUE)
crop_spr4<-brm(bf4, data = sprcrop_1.df, prior = bprior4,iter=4000,family="hurdle_gamma",control = list(adapt_delta=0.9999, max_treedepth = 12), core=4)
thank you in advance
```