hydromodpy.calibration.adapters.da_mh_gp_adapter#

Delayed-Acceptance Metropolis-Hastings with Gaussian-process surrogate.

Two-stage MCMC for expensive simulators: stage 1 filters proposals with a sklearn GaussianProcessRegressor surrogate of the log-posterior; stage 2 corrects the acceptance ratio with one full-model call, so the chain targets the exact posterior. The surrogate is retrained every retrain_interval new evaluations. The objective is assumed to return RMSE; the log-likelihood is built internally as -0.5 * (RMSE / sigma_noise)**2. The sampler pulls evaluations from the engine via a background thread (like scipy_adapter).

Classes

DaMhGpOptimizer(space, *[, max_iter, ...])

Delayed-Acceptance Metropolis-Hastings with GP surrogate.