simulate_choices: Simulate choice data
In RprobitB: Bayesian Probit Choice Modeling

simulate_choices

R Documentation

Simulate choice data

Description

This function simulates choice data from a probit model.

Usage

simulate_choices(
  form,
  N,
  T = 1,
  J,
  re = NULL,
  alternatives = NULL,
  ordered = FALSE,
  ranked = FALSE,
  base = NULL,
  covariates = NULL,
  true_parameter = list()
)

Arguments

`form`	[`formula`] A model description with the structure `choice ~ A \| B \| C`, where `choice` is the name of the dependent variable (the choices), `A` are names of alternative and choice situation specific covariates with a coefficient that is constant across alternatives, `B` are names of choice situation specific covariates with alternative specific coefficients, and `C` are names of alternative and choice situation specific covariates with alternative specific coefficients. Multiple covariates (of one type) are separated by a `+` sign. By default, alternative specific constants (ASCs) are added to the model. They can be removed by adding `+0` in the second spot. In the ordered probit model (`ordered = TRUE`), the `formula` object has the simple structure `choice ~ A`. ASCs are not estimated.
`N`	[`integer(1)`] The number of decision makers.
`T`	[`integer(1)` \| `integer(N)`] The number of choice occasions or a vector of decider-specific choice occasions of length `N`.
`J`	[`integer(1)`] The number >= 2 of choice alternatives.
`re`	[`character()` \| `NULL`] Names of covariates with random effects. If `re = NULL` (the default), there are no random effects. To have random effects for the ASCs, include `"ASC"` in `re`.
`alternatives`	[`character()`] The names of the choice alternatives. If not specified, the choice set is defined by the observed choices. If `ordered = TRUE`, `alternatives` is assumed to be specified with the alternatives ordered from worst to best.
`ordered`	[`logical(1)`] If `TRUE`, the choice set `alternatives` is assumed to be ordered from worst to best.
`ranked`	[`logical(1)`] Are the alternatives ranked?
`base`	[`character(1)`] The name of the base alternative for covariates that are not alternative specific (i.e. type 2 covariates and ASCs). Ignored and set to `NULL` if the model has no alternative specific covariates (e.g. in the ordered probit model). By default, `base` is the last element of `alternatives`.
`covariates`	[`list`] A named list of covariate values. Each element must be a vector of length equal to the number of choice occasions and named according to a covariate. Covariates for which no values are supplied are drawn from a standard normal distribution.
`true_parameter`	[`list`] A named list with true parameter values for `alpha`, `C`, `s`, `b`, `Omega`, `Sigma`, `Sigma_full`, `beta`, `z`, `d` for the simulation. See the vignette on model definition for definitions of these variables.

Details

See the vignette on choice data for more details.

Value

An object of class RprobitB_data.

Examples

### simulate data from a binary probit model with two latent classes
data <- simulate_choices(
  form = choice ~ cost | income | time,
  N = 100,
  T = 10,
  J = 2,
  re = c("cost", "time"),
  alternatives = c("car", "bus"),
  true_parameter = list(
    "alpha" = c(-1, 1),
    "b" = matrix(c(-1, -1, -0.5, -1.5, 0, -1), ncol = 2),
    "C" = 2
  )
)

### simulate data from an ordered probit model
data <- simulate_choices(
  form = opinion ~ age + gender,
  N = 10,
  T = 1:10,
  J = 5,
  alternatives = c("very bad", "bad", "indifferent", "good", "very good"),
  ordered = TRUE,
  covariates = list(
    "gender" = rep(sample(c(0, 1), 10, replace = TRUE), times = 1:10)
  )
)

### simulate data from a ranked probit model
data <- simulate_choices(
  form = product ~ price,
  N = 10,
  T = 1:10,
  J = 3,
  alternatives = c("A", "B", "C"),
  ranked = TRUE
)

RprobitB documentation built on Aug. 26, 2025, 1:08 a.m.