I have fitted a model in RStan and performed loo-cv with the `loo`

package by following this vignette Writing Stan programs for use with the loo package • loo

However some observations have pareto `k>0.7`

. I then try to redo loo with `moment_match = TRUE`

but nothing appears to happen - I get back exactly the same elpd and pareto k values within about 1 second of running the command. I’m also confused because the vignette about moment matching Avoiding model refits in leave-one-out cross-validation with moment matching seems to have different arguments in the `loo`

function to me: `loo2 <- loo(fit, moment_match = TRUE)`

where` fit <- sampling(stanmodel, data = standata, seed = seed, refresh = 0)`

. Does this mean I have to use this format for it to work? My code is:

```
require(rstan)
require(loo)
fit <- stan(file = 'mymodel.stan',
data = mydata,
iter = 2000, chains = 4)
loglik <- extract_log_lik(fit,c('log_lik'),merge_chains=FALSE)
loo_original <- loo(loglik, r_eff=relative_eff(exp(loglik)),cores=4,save_psis = TRUE)
loo_moment_match <- loo(loglik, r_eff=relative_eff(exp(loglik)),cores=1,moment_match = TRUE,overwrite=TRUE)
```

I have also tried without `cores=1, overwrite=TRUE`

.