get_draws() returns the calibrated fixed-effect draws of a stack_direct
fit: the draws of the stacked fit after the Cholesky calibration
correction (CCC), which gives them the mean and covariance of the target.
Usage
get_draws(x, ...)
# Default S3 method
get_draws(x, ...)
# S3 method for class 'pvstackr_fit'
get_draws(x, ...)
# S3 method for class 'pvstackr_legacy_psis_inspection'
get_draws(x, ...)Value
A numeric matrix with one row per draw of the stacked fit and one
column per fixed effect, named as in the estimate table (such as
b_Intercept). NULL for a fit made with return_draws = FALSE (such
as the bundled example fit), for a blocked fit, and for per_pv and
stack_psis fits.
get_draws() stops with an error if the fit was changed after it was
created, and for the inspection object that
pv_migrate_legacy_psis_fit() makes from a stack_psis fit of an
earlier pvstackr version, which has no draws.
Details
A fit keeps these draws only with return_draws = TRUE, the default of
pv_control(). per_pv and stack_psis fits keep their draws in
get_diagnostics() instead; "The fit object" in
pvstackr_object_contracts says where.
See also
pv_fit_direct() for how the draws are calibrated.
Other pvstackr-accessors:
get_diagnostics(),
get_estimates(),
get_target()
Examples
path <- system.file(
"extdata", "examples", "pisa_tiny_stack_direct.rds", package = "pvstackr"
)
if (nzchar(path)) {
fit <- readRDS(path)$fit
get_draws(fit) # NULL: the example fit was saved without its draws
}
#> NULL