idefix (version 0.2.4)

Decode: Coded choice set to character choice set.

Description

Transforms a coded choice set into a choice set containing character attribute levels, ready to be used in a survey.

Usage

Decode(set, lvl.names, coding, alt.cte = NULL, c.lvls = NULL)

Arguments

set

A numeric matrix which represents a choice set. Each row is a profile.

lvl.names

A list containing character vectors with the values of each level of each attribute.

coding

A character vector denoting the type of coding used for each attribute. See also Profiles.

alt.cte

A binary vector indicating for each alternative if an alternative specific constant is present. The default is NULL.

c.lvls

A list containing numeric vectors with the attributelevels for each continuous attribute. The default is NULL.

Value

A character matrix which represents the choice set.

Details

In lvl.names, the number of character vectors in the list should equal the number of attributes in de choice set. The number of elements in each character vector should equal the number of levels for that attribute.

Valid arguments for coding are C, D and E. When using C the attribute will be treated as continuous and no coding will be applied. All possible levels should then be specified in c.lvls. If D (dummy coding) is used contr.treatment will be applied to that attribute. The first attribute wil be used as reference level. For E (effect coding) contr.sum is applied, in this case the last attributelevel is used as reference level.

Examples

# NOT RUN {
# Example without continuous attributes.
l <- c(3, 4, 2) # 3 Attributes.
c <- c("D", "E", "D") # Coding.
# All profiles.
p <- Profiles(lvls = l, coding = c)
cs <- p[c(4, 8), ] # Choice set 
# Levels as they should appear in survey. 
al <- list(
 c("$50", "$75", "$100"), # Levels attribute 1.
 c("2 min", "15 min", "30 min", "50 min"), # Levels attribute 2.
 c("bad", "good") # Levels attribute 3.
) 
# Decode
Decode(set = cs, lvl.names = al, coding = c, alt.cte = c(0, 0)) 

# Example with continuous attribute.
l <- c(3, 4, 2) # 3 Attributes.
c <- c("D", "C", "D") # Coding.
cl <- list(c(50, 75, 80, 100))
# All profiles.
p <- Profiles(lvls = l, coding = c, c.lvls = cl)
cs <- p[c(4, 8), ] # Set. 
a <- c(1, 0) # Alternative specific constant. 
cs <- cbind(a, cs) # set with alt.cte
# Levels as they should appear in survey. 
al <- list(
  c("$50", "$75", "$100"), # Levels attribute 1.
  c("50 min", "75 min", "80 min", "100 min"), # Levels attribute 2.
  c("bad", "good") # Levels attribute 3.
) 
# Decode
Decode(set = cs, lvl.names = al, coding = c, alt.cte = c(1, 0), c.lvls = cl) 
# }