There is currently no public API in the loo package to subset a psis object by observation index. Downstream packages that need this functionality are forced to manually manipulate the internal structure of psis objects.
For example, bayesplot has had this workaround sitting with a FIXME comment : https://github.com/stan-dev/bayesplot/blob/master/R/ppc-loo.R#L722-L738
Would it be possible to export a subset.psis() S3 method or a subset_psis() helper? That way downstream code can drop the fragile workaround and rely on a stable API.
There is currently no public API in the
loopackage to subset apsisobject by observation index. Downstream packages that need this functionality are forced to manually manipulate the internal structure ofpsisobjects.For example, bayesplot has had this workaround sitting with a FIXME comment : https://github.com/stan-dev/bayesplot/blob/master/R/ppc-loo.R#L722-L738
Would it be possible to export a
subset.psis()S3 method or asubset_psis()helper? That way downstream code can drop the fragile workaround and rely on a stable API.