dfr_dist_series objects now also inherit from
dist_structure (from the dist.structure
package). Series-system topology generics work out of the box:
phi, min_paths, min_cuts,
system_signature, plus the defaults from
dist.structure (structural_importance,
reliability, dual, is_coherent,
critical_states, system_lifetime,
system_censoring, birnbaum_importance,
criticality_importance,
vesely_fussell_importance,
substitute_component,
compose_systems).
The local ncomponents and component
generics are removed and re-exported from dist.structure
instead. This eliminates a latent namespace collision when both
serieshaz and dist.structure are loaded.
Existing user code that calls ncomponents(sys) or
component(sys, j) is unaffected.
dfr_dist_series is now
c("dfr_dist_series", "dfr_dist", "dist_structure", "univariate_dist", "dist").
The "dist_structure" insertion is positioned after
"dfr_dist" so the optimized flexhaz survival,
hazard, sampler, and CDF methods continue to dispatch first;
"dist_structure" provides defaults only for generics that
flexhaz/serieshaz do not already
implement.Decomposed system score and Hessian: instead of
numDeriv on the full system log-likelihood, both are
computed per-component. When components provide analytical
score_fn/hess_fn, the cumulative hazard
derivatives are extracted analytically (via the all-censored trick); the
hazard derivatives use
numDeriv::jacobian/numDeriv::hessian
per-component (lower-dimensional). The Hessian exploits block structure:
cross-component blocks reuse rate Jacobians from the score. Roughly
m-fold speedup for systems with m components.
Input validation for component() and
component_hazard(): the j parameter now
rejects non-integer, NA, and vector inputs (previously
j = 1.5 silently truncated to j = 1).
component_hazard() closure now reads the system
parameter vector lazily, so it reflects updates to sys$par
after construction (e.g., after fitting).
Guard against zero-parameter components: the constructor now
rejects n_par entries less than 1.
Aligned sys_cum_haz initialization to
numeric(length(t)) for explicit vectorization consistency
with sys_rate.
Added numDeriv to Imports (previously an undeclared
transitive dependency through flexhaz).
Removed Remotes field from DESCRIPTION (CRAN
submission blocker).
component_hazard()
closure: default parameters were eagerly captured at closure-creation
time, causing the closure to use outdated values if sys$par
was updated post-construction.delta = -1),
boundary conditions (t = 0), j parameter
validation, sample_components error path, and decomposed
score accuracy.Initial release.
dfr_dist_series() constructor composes multiple
dfr_dist components into a series system distribution where
the system hazard is the sum of component hazards.dfr_dist: hazard, survival, CDF,
density, quantile, sampling, log-likelihood, score, Hessian, and MLE
fitting all work automatically.cum_haz_rate; numerical integration fallback
otherwise.ncomponents(),
component(), param_layout(),
component_hazard(), sample_components().dfr_dist_series can be
a component in another series system).