use_contrasts.default function

Default method for use_contrasts

If a user doesn't specify a contrast matrix, use the defaults from options(). If the user tries to use something we don't know how to work with, throw a warning that we'll be using the defaults from options().

## Default S3 method:
use_contrasts(
  factor_col,
  code_by = NA,
  reference_level = NA,
  set_intercept = NA,
  drop_trends = NA,
  labels = NULL,
  as_is = FALSE,
  ...
)

Arguments

• factor_col: A factor vector, eg from df$factorVarName
• code_by: Some object that's not a matrix or function. If NA, no warning will be thrown, and the default contrasts will be used. A warning will be thrown if it's not NA.
• reference_level: Not used
• set_intercept: Not used
• drop_trends: Not used
• labels: A vector of labels to apply to the matrix column names, default
• as_is: Logical, default FALSE, whether to leave the resulting matrix
• ...: Additional arguments, not used

Returns

Contrast matrix, using the ordered or unordered default from options()

Examples

use_contrasts(gl(5,1), helmert_code) # a function
my_matrix <- helmert_code(5)
use_contrasts(gl(5,1), my_matrix) # a matrix