enhanceFunctionWithBoundaries: Modifies function to return a penalty value for parameters...

In simplaceUtil: Provides Utility Functions and ShinyApps to work with the modeling framework 'SIMPLACE'

Modifies function to return a penalty value for parameters outside boundaries

Description

The method takes a function as well as values for lower and upper boundaries and returns a modified function. The modified function returns the value of the original function when the parameters are within boundaries and the penalty value otherwise.

Usage

enhanceFunctionWithBoundaries(
  fun,
  l_bound,
  u_bound,
  penalty_value = Inf,
  boundary_fun = NULL,
  param_pos = 1,
  ...
)

Arguments

fun	function to be modified
l_bound	vector with lower boundary values
u_bound	vector with upper boundary values
penalty_value	value if parameter outside boundaries
boundary_fun	optional function for complex boundary conditions
param_pos	argument position of the parameter
...	arguments passed to original function

Details

Optionally an own function can be supplied to calculate whether the parameter is valid. The boundary function must take 3 arguments: parameter, lower boundary and upper boundary and must return TRUE or FALSE.

A main use case of this method are optimisation / calibration tasks. If the optimisation method and the function to optimise are both ignorant to boundaries one can turn the function into a boundary sensitive one.

Value

a modified function that considers boundaries

Examples

sqrt_bd <- enhanceFunctionWithBoundaries(sqrt, 0, 10)
sqrt_bd(-1)
sqrt_bd(1)
sqrt_bd(11)

simplaceUtil documentation built on Aug. 6, 2024, 3:01 p.m.