Set computational options for the sampling algorithms
sampler_control(
add.outer.R = NULL,
recompute.e = TRUE,
CG = NULL,
block = TRUE,
block.V = TRUE,
auto.order.block = TRUE,
chol.control = chol_control(),
max.size.cps.template = 100,
PG.approx = TRUE,
PG.approx.m = -2L,
CRT.approx.m = 20L
)
A list with specified computational options used by various sampling functions.
whether to add the outer product of the constraint matrix for a better conditioned solve system for blocks. This is done by default when using blocked Gibbs sampling for blocks with constraints.
when FALSE
, residuals or linear predictors are only computed at the start of the simulation.
This may give a modest speedup but in some cases may be less accurate due to round-off error accumulation.
Default is TRUE
.
use a conjugate gradient iterative algorithm instead of Cholesky updates for sampling
the model's coefficients. This must be a list with possible components max.it
,
stop.criterion
, verbose
, preconditioner
and scale
.
See the help for function CG_control
, which can be used to specify these options.
Conjugate gradient sampling is currently an experimental feature that can be used for
blocked Gibbs sampling but with some limitations.
if TRUE
, the default, all coefficients are sampled in a single block. Alternatively, a list of
character vectors with names of model components whose coefficients should be sampled together in blocks.
if TRUE
, the default, all coefficients of reg
and gen
components
in a variance model formula are sampled in a single block. Alternatively, a list of
character vectors with names of model components whose coefficients should be sampled together in blocks.
whether Gibbs blocks should be ordered automatically in such a way that those with the most sparse design matrices come first. This way of ordering can make Cholesky updates more efficient.
options for Cholesky decomposition, see chol_control
.
maximum allowed size in MB of the sparse matrix serving as a template for the sparse symmetric crossproduct X'QX of a dgCMatrix X, where Q is a diagonal matrix subject to change.
whether Polya-Gamma draws for logistic binomial models are
approximated by a hybrid gamma convolution approach. If not, BayesLogit::rpg
is used, which is exact for some values of the shape parameter.
if PG.approx=TRUE
, the number of explicit gamma draws in the
sum-of-gammas representation of the Polya-Gamma distribution. The remainder (infinite)
convolution is approximated by a single moment-matching gamma draw. Special values are:
-2L
for a default choice depending on the value of the shape parameter
balancing performance and accuracy, -1L
for a moment-matching normal approximation,
and 0L
for a moment-matching gamma approximation.
scalar integer specifying the degree of approximation to sampling from a Chinese Restaurant Table distribution. The approximation is based on Le Cam's theorem. Larger values yield a slower but more accurate sampler.
D. Bates, M. Maechler, B. Bolker and S.C. Walker (2015). Fitting Linear Mixed-Effects Models Using lme4. Journal of Statistical Software 67(1), 1-48.
Y. Chen, T.A. Davis, W.W. Hager and S. Rajamanickam (2008). Algorithm 887: CHOLMOD, supernodal sparse Cholesky factorization and update/downdate. ACM Transactions on Mathematical Software 35(3), 1-14.