approximation_models

Specification of an unordered ensemble of low-fidelity approximations

Specification

• Alias: unordered_model_fidelities

• Arguments: STRINGLIST

Description

An unordered or “non-hierarchical” ensemble surrogate manages an unordered set of low-fidelity model approximations, each of which may include hyper-parameter resolution controls (in the case of a simulation model) or additional model recursions.

Any corresponding sequence specifications within methods (e.g., quadrature_order_sequence, sparse_grid_level_sequence, expansion_order_sequence, etc. within stochastic expansion methods) should be synchronized with the order in the model listing.

Internal to the ensemble surrogate model, subsets of the model ensemble may be active for any given evaluation, as dictated by the iterative algorithm in use.

Examples

model,
 id_model = 'NONHIERARCH'
 surrogate ensemble
   unordered_model_fidelities = 'LF1' 'LF2'
   truth_model_pointer = 'HF'

model,
 id_model = 'LF1'
 simulation
   interface_pointer = 'LF1_DRIVER'
          solution_level_cost = 1.

model,
 id_model = 'LF2'
 simulation
   interface_pointer = 'LF2_DRIVER'
          solution_level_cost = 2.4

model,
 id_model = 'HF'
 simulation
   interface_pointer = 'HF_DRIVER'
          solution_level_cost = 256.