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().
Usage
# 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
Value
Contrast matrix, using the ordered or unordered default from
options()
Examples
use_contrasts(gl(5,1), helmert_code) # a function
#> 2 3 4 5
#> 1 -0.5 -0.3333333 -0.25 -0.2
#> 2 0.5 -0.3333333 -0.25 -0.2
#> 3 0.0 0.6666667 -0.25 -0.2
#> 4 0.0 0.0000000 0.75 -0.2
#> 5 0.0 0.0000000 0.00 0.8
my_matrix <- helmert_code(5)
use_contrasts(gl(5,1), my_matrix) # a matrix
#> 2 3 4 5
#> 1 -0.5 -0.3333333 -0.25 -0.2
#> 2 0.5 -0.3333333 -0.25 -0.2
#> 3 0.0 0.6666667 -0.25 -0.2
#> 4 0.0 0.0000000 0.75 -0.2
#> 5 0.0 0.0000000 0.00 0.8