apollo_prepareProb: Checks likelihood function

In apollo: Tools for Choice Model Estimation and Application

Checks likelihood function

Description

Checks that the likelihood function for the mode is in the appropriate format to be returned.

Usage

apollo_prepareProb(P, apollo_inputs, functionality)

Arguments

P	List of vectors, matrices or 3-dim arrays. Likelihood of the model components.
apollo_inputs	List grouping most common inputs. Created by function apollo_validateInputs.
functionality	Character. Setting instructing Apollo what processing to apply to the likelihood function. This is in general controlled by the functions that call apollo_probabilities, though the user can also call apollo_probabilities manually with a given functionality for testing/debugging. Possible values are: "components": For further processing/debugging, produces likelihood for each model component (if multiple components are present), at the level of individual draws and observations. "conditionals": For conditionals, produces likelihood of the full model, at the level of individual inter-individual draws. "estimate": For model estimation, produces likelihood of the full model, at the level of individual decision-makers, after averaging across draws. "gradient": For model estimation, produces analytical gradients of the likelihood, where possible. "output": Prepares output for post-estimation reporting. "prediction": For model prediction, produces probabilities for individual alternatives and individual model components (if multiple components are present) at the level of an observation, after averaging across draws. "preprocess": Prepares likelihood functions for use in estimation. "raw": For debugging, produces probabilities of all alternatives and individual model components at the level of an observation, at the level of individual draws. "report": Prepares output summarising model and choiceset structure. "shares_LL": Produces overall model likelihood with constants only. "validate": Validates model specification, produces likelihood of the full model, at the level of individual decision-makers, after averaging across draws. "zero_LL": Produces overall model likelihood with all parameters at zero.

Details

This function should be called inside apollo_probabilities, near the end of it, just before return(P). This function only performs checks on the shape of P, but does not change its values.

Value

Argument P with (for most functionalities) the original contents. Output depends on argument functionality.

• "components": Returns P without changes.

• "conditionals": Returns only the "model" component of argument P.

• "estimate": Returns only the "model" component of argument P.

• "gradient": Returns only the "model" component of argument P.

• "output": Returns argument P without any changes to its content, but gives names to unnamed elements.

• "prediction": Returns argument P without any changes.

• "preprocess": Returns argument P without any changes to its content, but gives names to elements corresponding to componentNames.

• "raw": Returns argument P without any changes.

• "report": Returns P without changes.

• "shares_LL": Returns argument P without any changes to its content, but gives names to unnamed elements.

• "validate": Returns argument P without any changes.

• "zero_LL": Returns argument P without any changes to its content, but gives names to unnamed elements.

apollo documentation built on April 3, 2025, 9:27 p.m.