biogeme.expressions.linear_utility module

Arithmetic expressions accepted by Biogeme: nary operators

Michel Bierlaire Sat Sep 9 15:29:36 2023

class biogeme.expressions.linear_utility.LinearTermTuple(beta, x)

Bases: NamedTuple

Parameters:

• beta (Beta)

• x (Variable)

class biogeme.expressions.linear_utility.LinearUtility(list_of_terms)

Bases: Expression

When the utility function is linear, it is expressed as a list of terms, where a parameter multiplies a variable.

Parameters:

list_of_terms (list[LinearTermTuple])

deep_flat_copy()

Provides a copy of the expression. It is deep in the sense that it generates copies of the children. It is flat in the sense that any MultipleExpression is transformed into the currently selected expression. The flat part is irrelevant for this expression.

Return type:

LinearUtility

recursive_construct_jax_function(numerically_safe)

Generates a function to be used by biogeme_jax. Must be overloaded by each expression

Return type:

Callable[[Array, Array, Array, Array], Array]

Returns:

the function takes two parameters: the parameters, and one row of the database.

Parameters:

numerically_safe (bool)

recursive_construct_pymc_model_builder()

PyMC builder for LinearUtility: - evaluate Beta (scalar) and Variable (per-observation) children - form elementwise products beta_k * x_k - stack along a new axis and sum to get the linear utility per observation

Return type:

PymcModelBuilderType