sim_choice: Simulate and estimate choices

In simulateDCE: Simulate Data for Discrete Choice Experiments

Simulate and estimate choices

Description

Simulate and estimate choices

Usage

sim_choice(
  designfile,
  no_sim = 10,
  respondents = 330,
  u,
  designtype = NULL,
  destype = NULL,
  bcoeff,
  decisiongroups = c(0, 1),
  manipulations = list(),
  estimate,
  chunks = 1,
  utility_transform_type = "simple",
  mode = c("parallel", "sequential"),
  preprocess_function = NULL,
  savefile = NULL
)

Arguments

designfile	path to a file containing a design.
no_sim	Number of runs i.e. how often do you want the simulation to be repeated
respondents	Number of respondents. How many respondents do you want to simulate in each run.
u	A list with utility functions. The list can incorporate as many decision rule groups as you want. However, each group must be in a list in this list. If you just use one group (the normal), this group still has to be in a list in the u list. As a convention name beta coefficients starting with a lower case "b"
designtype	Is it a design created with ngene, spdesign or idefix. use 'ngene', 'spdesign' or 'idefix. Ngene designs should be stored as the standard .ngd output. spdesign should be the spdesign object stored as an RDS file. Idefix objects should also be stored as an RDS file. If designtype is not specified, I try to guess what it is. This is especially helpful if you want to carry out a simulation for both spdesign designs and ngene designs at the same time.
destype	Deprecated. Use designtype instead.
bcoeff	List of initial coefficients for the utility function. List content/length can vary based on application. I ideally begins (but does not have to) with b and need be the same as those entered in the utility functions
decisiongroups	A vector showing how decision groups are numerically distributed
manipulations	A variable to alter terms of the utility functions examples may be applying a factor or applying changes to terms selectively for different groups
estimate	If TRUE models will be estimated. If false only a dataset will be simulated. Default is TRUE
chunks	The number of chunks determines how often results should be stored on disk as a safety measure to not loose simulations if models have already been estimated. For example, if no_sim is 100 and chunks = 2, the data will be saved on disk after 50 and after 100 runs.
utility_transform_type	How the utility function you entered is transformed to the utility function required for mixl. You can use the classic way (simple) where parameters have to start with "b" and variables with "alt" or the more flexible (but potentially error prone) way (exact) where parameters and variables are matched exactly what how the are called in the dataset and in the bcoeff list. Default is "simple". In the long run, simple will be deleted, as exact should be downwards compatible.
mode	Set to "parallel" if parts should be run in parallel mode
preprocess_function	= NULL You can supply a function that reads in external data (e.g. GIS coordinates) that will be merged with the simulated dataset. Make sure the the function outputs a data.frame that has a variable called ID which is used for matching.
savefile	Indicate a path if you want to store the results after each design simulation locally. This is useful in case you fear that your computer crashes

Value

a list with all information on the run

Examples

bcoeff <- list(
  basc = -1.2,
  basc2 = -1.4,
  baction = 0.1,
  badvisory = 0.4,
  bpartnertest = 0.3,
  bcomp = 0.02
)
ul <- list(
  u1 =
    list(
     #' # model specification ----------------------------------------------
v1 <- V.1 ~ basc +
  baction      * alt1.b +
  badvisory    * alt1.c +
  bpartnertest * alt1.d +
  bcomp        * alt1.p,

v2 <- V.2 ~ basc2 +
  baction      * alt2.b +
  badvisory    * alt2.c +
  bpartnertest * alt2.d +
  bcomp        * alt2.p,
 v3 <- V.3 ~ 0
    )
)

sim_choice(
  designfile = system.file("extdata", "agora", "altscf_eff.ngd", package = "simulateDCE"),
  no_sim = 2,
  respondents = 144,
  u = ul,
  bcoeff = bcoeff,
  estimate = FALSE
)

simulateDCE documentation built on Aug. 8, 2025, 6:37 p.m.