Sets factor/loadings pairs to zero if doing so improves the variational
lower bound (ELBO). See flash for examples of usage.
flash_nullcheck(flash, kset = NULL, remove = TRUE, tol = NULL, verbose = NULL)A flash or flash_fit object.
A vector of integers specifying which factors to nullcheck.
If kset = NULL, then all existing factors will be checked.
Whether to remove factors that have been set to zero from the
flash object. Note that this might change the indices of existing
factors.
The "tolerance" parameter: if a factor does not improve the ELBO
by at least tol, then it will be set to zero. Note that
flash_nullcheck does not respect "global" tolerance parameters set
by flash_set_conv_crit (which only affects the convergence
tolerance for greedy fits and backfits). The default tolerance is
\(np\sqrt{\epsilon}\), where \(n\) is the
number of rows in the dataset, \(p\) is the number of columns, and
\(\epsilon\) is equal to .Machine$double.eps.
When and how to display progress updates. For nullchecks,
updates are only displayed when verbose > 0.
The flash object from argument flash, with
factors that do not improve the ELBO by at least tol either set
to zero or removed (depending on the argument to parameter remove).