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Compute the calibration loss from N replicate trial outputs

loss_from_stats.Rd

Combines per-replicate parse_dynamic_fire_logs() outputs into the multi- component weighted loss against observed targets from save_observed_fire_targets().

Usage

loss_from_stats(
  reps,
  observed,
  weights = c(count = 1, size = 1, area_fuel = 0, severity = 0)
)

Arguments

reps

List. Each element is the return value of parse_dynamic_fire_logs() for one replicate.

observed

List. Output of save_observed_fire_targets(). Must contain $primary (or $fru59 back-compat alias) with $lambda_obs, $n_fires_by_year, $fire_sizes_ha. May contain $primary$area_by_fuel_ha, $primary$severity_dist, $fuel_code_to_base, and $pixel_area_ha to activate Tier 2 components.

weights

Named numeric vector. Components: count, size, area_fuel, severity. Missing components default to 0.

Value

Named list with total (the scalar minimised by DEoptim), components (per-component contributions), and weights (echoed weights).

Details

Components:

  • L_count = |mean(n_fires_sim) - lambda_obs| / sd(n_fires_obs) – annual-rate match against the primary ecoregion target.

  • L_size = KS_D(empirical CDF of sim sizes, empirical CDF of obs sizes) – shape match for the fire-size distribution.

  • L_area_fuel: chi-squared distance between simulated and observed burn-area-by-base-fuel-type proportions. Simulated area-by-fuel comes from each event's ignition fuel code times its DamagedSites, mapped to base fuel types via observed$fuel_code_to_base. Skipped (contributes 0) when either observed$primary$area_by_fuel_ha is NULL or observed$fuel_code_to_base is missing.

  • L_severity: chi-squared distance between simulated and observed severity-class proportions. Simulated severities come from each event's MeanSeverity binned into integer classes 1..5; observed comes from observed$primary$severity_dist (a 5-element named numeric vector summing to 1). Skipped when observed is NULL.

All component values are unitless and non-negative; chi-squared components use a small epsilon in the denominator to avoid division by zero on empty observed bins.

See also

Other Dynamic Fire calibration helpers: apply_calibrated_hi_prop(), apply_calibrated_ignprob(), bc_fuel_code_to_base(), build_calibration_scenario_template(), build_calibration_spinup_scenario(), calibrate_dynamic_fire(), calibration_par_names(), default_severity_prior_sturtevant2009(), parse_dynamic_fire_logs(), patch_fire_config(), run_calibration_spinup(), save_observed_fire_targets(), sim_landis(), sim_mock(), sim_r_reimpl()