Wrapped for create_attributes, create_design_df, and create_value_dummies

create_predictors.R

################################################
# Define function: create_predictors
# Creates randomly generated data sets containing
# all design variables, attributes, and dummy
# variables for the right-hand side of the conjoint
# analysis (excludes the outcome variable),
# based on specified data parameter values.
# Data are "long," sucht hat each row of the data 
# is a conjoint profile.
#
# Arguments:
# N: number of participants
# K: number of choices completed
# W: number of profiles per screen
# attr_n: number of attributes overall
# attr_levels: list (or vector)
#              of possible levels for each attribute.
# attr_names: names of attributes. defaults a generic
#             nmae followed by the index of the attribute
#             in attr_levels.
# probs: list (or vector) of probabilities used to randomly
#        draw values from the attribute levels vectors and assign 
#        them to profiles.
################################################

create_predictors <- function(N,
                              K,
                              W = 2,
                              attr_n,
                              attr_levels,
                              attr_names = NULL,
                              probs = NULL) {
  
  # Number of unique profiles (rows in final data frame)
  n_profiles <- N * K * W
  
  # Generate design dataframe
  temp <- create_design_df(N = N, K = K, W = W)
  
  # Generate specified number of attributes with specified
  # properties.
  attr_df <- create_attributes(
    attr_levels = attr_levels,
    n_profiles = n_profiles,
    attr_names = attr_names,
    probs = probs
  )
  
  # If attribute names not provided in function, create vector
  # of function-generated attribute namesthe names
  if (is.null(attr_names)) {
    attr_names <- colnames(attr_df)
  }
  
  # Generate dummy variables for each attribute value
  temp_attribs <- create_value_dummies(attr_df = attr_df,
                                       attr_levels = attr_levels)
  
  # Combine all attributes, dummies, and design variables into
  # a single data frame
  df <- dplyr::bind_cols(temp, temp_attribs)
  
  # Return all data created (excludes outcomes)
  df
}

#############################################################
# Example
##############################################################

# Specify example parameters for the data

 #N <- 50
 #K <- 3
 #W <- 2
 #attr_n <- 3
 #attr_levels <- list(c(1, 2, 3), c("a", "b", "c", "d", "e"), c(5))
 #attr_names = NULL
 #probs = NULL
 # 
 # 
 # create_predictors(
 #   N = N,
 #   K = K,
 #   W = W,
 #   attr_n = attr_n,
 #   attr_levels = attr_levels,
 #   attr_names = attr_names,
 #   probs = probs
 # )