A numeric parameter function representing parameters for the spike-and-slab
prior used by embed::step_pca_sparse_bayes().
prior_slab_dispersion(range = c(-1/2, log10(3)), trans = transform_log10())prior_mixture_threshold(range = c(0, 1), trans = NULL)
A two-element vector holding the defaults for the smallest and largest possible values, respectively. If a transformation is specified, these values should be in the transformed units.
A trans object from the scales package, such as
scales::transform_log10() or scales::transform_reciprocal(). If not provided,
the default is used which matches the units used in range. If no
transformation, NULL.
prior_slab_dispersion() is related to the prior for the case where a PCA
loading is selected (i.e. non-zero). Smaller values result in an increase in
zero coefficients.
prior_mixture_threshold() is used to threshold the prior to determine which
parameters are non-zero or zero. Increasing this parameter increases the
number of zero coefficients.