Convert the group column to a factor with the desired VVIQ classification

Convert the group column to a factor with the desired VVIQ classification

Usage

factor_groups(df, n_groups = 2, contrast_base = NULL, ...)

Arguments

df: A data frame containing a group column with VVIQ groups among "Aphantasia", "Hypophantasia", "Typical" and "Hyperphantasia".
n_groups: An integer indicating the number of groups to create, which reflect specific classifications of VVIQ scores: two groups mean grouping Aphants and Hypophants on one end and Typical and Hyperphants on the other, three groups mean separating Aphants, Hypophants and Typical but removing Hyperphants (that have been shown to have distinct characteristics), and four groups mean separating and keeping all four groups. Default is 2.
contrast_base: Optional. An integer indicating the base level for the contrasts. By default, the base level is set to the Typical group for all classifications. This argument allows you to set a different base level (i.e., a different group to compare against for planned comparisons).
...: Additional arguments passed to add_factor_contrasts().

Value

A data frame with the group column converted to a factor with contrasts added, and the levels set according to the number of groups.

Examples

df <- factor_groups(survey_data, n_groups = 2)
contrasts(df$group)
#>            _aphantasia
#> Aphantasia           1
#> Typical              0

df <- factor_groups(survey_data, n_groups = 3)
contrasts(df$group)
#>               _aphantasia _hypophantasia
#> Aphantasia              1              0
#> Hypophantasia           0              1
#> Typical                 0              0

df <- factor_groups(survey_data, n_groups = 4)
contrasts(df$group)
#>                _aphantasia _hypophantasia _hyperphantasia
#> Aphantasia               1              0               0
#> Hypophantasia            0              1               0
#> Typical                  0              0               0
#> Hyperphantasia           0              0               1

# Choosing Aphantasia as the reference level for the contrasts
# (i.e., for planned comparisons)
df <- factor_groups(survey_data, n_groups = 4, contrast_base = 1)
contrasts(df$group)
#>                _hypophantasia _typical _hyperphantasia
#> Aphantasia                  0        0               0
#> Hypophantasia               1        0               0
#> Typical                     0        1               0
#> Hyperphantasia              0        0               1