Returns a list of the design matrix X and updated pars and randPars to include any dummy-coded categorical or interaction variables.

Recodes the data and returns a list of the encoded design matrix (X) as well as two vectors (pars and randPars) with discrete (categorical) variables and interaction variables added to X, pars, and randPars.

Usage

recodeData(data, pars, randPars)

Arguments

data

The data, formatted as a data.frame object.

pars

The names of the parameters to be estimated in the model. Must be the same as the column names in the data argument. For WTP space models, do not include price in pars - it should instead be defined by the scalePar argument.

randPars

A named vector whose names are the random parameters and values the distribution: 'n' for normal or 'ln' for log-normal. Defaults to NULL.

Value

A list of the design matrix (X) and two vectors (pars and randPars) with discrete (categorical) variables and interaction variables added.

Examples

library(logitr)

data(yogurt)

# Recode the yogurt data
result <- recodeData(
    data = yogurt,
    pars = c("price", "feat", "brand", "price*brand"),
    randPars = c(feat = "n", brand = "n")
)

result$formula
#> ~price + feat + brand + price * brand
#> <environment: 0x556db34282f0>
result$pars
#> [1] "price"              "feat"               "brandhiland"       
#> [4] "brandweight"        "brandyoplait"       "price:brandhiland" 
#> [7] "price:brandweight"  "price:brandyoplait"
result$randPars
#>         feat  brandhiland  brandweight brandyoplait 
#>          "n"          "n"          "n"          "n" 
head(result$X)
#>   price feat brandhiland brandweight brandyoplait price:brandhiland
#> 1   8.1    0           0           0            0               0.0
#> 2   6.1    0           1           0            0               6.1
#> 3   7.9    0           0           1            0               0.0
#> 4  10.8    0           0           0            1               0.0
#> 5   9.8    0           0           0            0               0.0
#> 6   6.4    0           1           0            0               6.4
#>   price:brandweight price:brandyoplait
#> 1               0.0                0.0
#> 2               0.0                0.0
#> 3               7.9                0.0
#> 4               0.0               10.8
#> 5               0.0                0.0
#> 6               0.0                0.0