Objective Function for Rate Yield Optimization

Source: R/calibrate_yield.R

Computes the squared difference between the base premium rate implied by a candidate rate_yield and the observed base_premium_rate_expected. Intended for use with optimization routines (e.g., DEoptim) to invert the RMA premium-rate pipeline.

rate_yield_optimizer(
  rate_yield,
  base_premium_rate_expected,
  reference_amount,
  reference_rate,
  fixed_rate,
  rate_differential_factor,
  unit_residual_factor,
  exponent_value,
  prior_year_reference_amount,
  prior_year_reference_rate,
  prior_year_fixed_rate,
  prior_year_rate_differential_factor,
  prior_year_unit_residual_factor,
  prior_year_exponent_value,
  rate_yield_control = rfcipPackage_controls()
)

Arguments

rate_yield

Numeric. Candidate yield per acre evaluated by the optimizer.

base_premium_rate_expected

Numeric. Target base premium rate to match.

reference_amount

Numeric. Current-year reference yield for ratio calculation.

reference_rate

Numeric. Rate component for current-year base rate calculation.

fixed_rate

Numeric. Fixed increment added after exponentiation (current year).

rate_differential_factor

Numeric. Differential factor for current-year base premium.

unit_residual_factor

Numeric. Unit residual factor for current-year base premium.

exponent_value

Numeric. Exponent used on current-year yield ratio.

prior_year_reference_amount

Numeric. Reference yield for the prior year.

prior_year_reference_rate

Numeric. Rate component for prior-year base rate.

prior_year_fixed_rate

Numeric. Fixed increment for prior-year calculation.

prior_year_rate_differential_factor

Numeric. Differential factor for prior-year premium.

prior_year_unit_residual_factor

Numeric. Unit residual factor for prior-year premium.

prior_year_exponent_value

Numeric. Exponent used on prior-year yield ratio.

rate_yield_control

List. Control settings from rfcipPackage_controls() forwarded to calc_base_premium_rate().

Value

Numeric. Squared error between computed and expected base premium rates; a large penalty (1e10) is returned if the result is not finite.