simulate_values: Simulate Values

In dRiftDM: Estimating (Time-Dependent) Drift Diffusion Models

Simulate Values

Description

Draw values, most likely model parameters.

Usage

simulate_values(
  lower,
  upper,
  k,
  distr = NULL,
  cast_to_data_frame = TRUE,
  add_id_column = "numeric",
  seed = NULL,
  ...
)

Arguments

lower, upper	Numeric vectors, indicating the lower/upper boundary of the drawn values.
k	Numeric, the number of values to be drawn for each value pair of lower/upper. If named numeric, the labels are used for the column names of the returned object
distr	Character, indicating which distribution to draw from. Currently available are: "unif" for a uniform distribution or "tnorm" for a truncated normal distribution. NUll will lead to "unif" (default).
cast_to_data_frame	Logical, controls whether the returned object is of type data.frame (TRUE) or matrix (FALSE). Default is TRUE
add_id_column	Character, controls whether an ID column should be added. Options are "numeric", "character", or "none". If "numeric" or "character" the column ID provides values from 1 to k of the respective type. If none, no column is added. Note that "character" casts all simulated values to character if the argument cast_to_data_frame is set to FALSE.
seed	Numeric, optional seed for making the simulation reproducable (see details)
...	Further arguments relevant for the distribution to draw from

Details

When drawing from a truncated normal distribution, users must provide values for the arguments means and sds. These are numeric vectors of the same size as lower and upper, and indicate the mean and the standard deviation of the normal distributions.

Value

If cast_to_data_frame is TRUE, a data.frame with k rows and at least length(lower);length(upper) columns. Otherwise a matrix with the same number of rows and columns. Columns are labeled either from V1 to Vk or in case lower and upper are named numeric vectors using the labels of both vectors.

If add_id_column is not "none", an ID column is provided of the respective data type.

The data type of the parameters will be numeric, unless add_id_column is "character" and cast_to_data_frame is FALSE. In this case the returned matrix will be of type character.

Examples

# Example 1: Draw from uniform distributions ------------------------------
lower <- c(a = 1, b = 1, c = 1)
upper <- c(a = 3, b = 4, c = 5)
values <- simulate_values(
  lower = lower,
  upper = upper,
  k = 50,
  add_id_column = "none"
)
summary(values)

# Example 2: Draw from truncated normal distributions ---------------------
lower <- c(a = 1, b = 1, c = 1)
upper <- c(a = 3, b = 4, c = 5)
means <- c(a = 2, b = 2.5, c = 3)
sds <- c(a = 0.5, b = 0.5, c = 0.5)
values <- simulate_values(
  lower = lower,
  upper = upper,
  distr = "tnorm",
  k = 5000,
  add_id_column = "none",
  means = means,
  sds = sds
)
quantile(values$a, probs = c(0.025, 0.5, 0.975))
quantile(values$b, probs = c(0.025, 0.5, 0.975))
quantile(values$c, probs = c(0.025, 0.5, 0.975))

dRiftDM documentation built on April 3, 2025, 7:48 p.m.