model-class: An S4 class Representing a Cognitive Model Object.

In ggdmcModel: Model Builders for 'ggdmc' Package

An S4 class Representing a Cognitive Model Object.

Description

The 'model' class stores information that defines how parameters in a cognitive model are associated with experimental conditions, responses, and other design factors. This object is typically created as part of the model specification process and is used as input to fitting functions or simulation routines.

Value

An object of class 'model', used to configure and fit cognitive decision models to experimental data.

Slots

parameter_map

A named list or structure indicating how each model parameter varies with experimental factors (e.g., which parameters depend on which conditions).

accumulators

A character vector naming the accumulators in the model (e.g., for racing models or diffusion models with multiple response alternatives).

factors

A named list where each element is a factor in the experimental design, and each value is a vector of levels for that factor.

match_map

A list specifying which responses are considered correct or incorrect for each condition. Typically used in decision models to differentiate match/non-match.

constants

A named list of model parameters that are fixed to user-defined values, rather than estimated.

cell_names

A character vector giving the names of each condition cell in the design Boolean array (e.g., 's1.d1.r1', 's1.d1.r2', 's1.d2.r1', etc.), derived from crossing factor levels.

parameter_x_condition_names

A character vector naming how each parameter is associated with particular condition cells.

model_boolean

A 3D logical array. Its dimensions are:

• slice: accumulators,

• row: cells (i.e., conditions),

• column: free parameters

, indicating whether a parameter is free to vary for a given accumulator and condition.

pnames

A character vector listing the names of all free parameters in the model.

npar

An integer giving the total number of free parameters in the model.

type

A character string indicating the type of model (e.g., 'fastdm' for the diffusion model described in Voss, Rothermund, and Voss (2004) <doi:10.3758/BF03196893>.)

Structure

An object of class 'model' contains the following slots:

Purpose

This class object encapsulates all necessary mappings and constraints required for model fitting. It is used by the fitting engine to determine which parameters vary, what parameters are fixed, and how each condition affects the model structure.

ggdmcModel documentation built on Aug. 8, 2025, 7:50 p.m.