Parameters for exponents

These parameters help model cases where an exponent is of interest (e.g. degree() or spline_degree()) or a product is used (e.g. prod_degree).

degree(range = c(1, 3), trans = NULL)

degree_int(range = c(1L, 3L), trans = NULL)

spline_degree(range = c(1L, 10L), trans = NULL)

prod_degree(range = c(1L, 2L), trans = NULL)

Arguments

range

A two-element vector holding the defaults for the smallest and largest possible values, respectively. If a transformation is specified, these values should be in the transformed units.

trans

A trans object from the scales package, such as scales::transform_log10() or scales::transform_reciprocal(). If not provided, the default is used which matches the units used in range. If no transformation, NULL.

Details

degree() is helpful for parameters that are real number exponents (e.g. x^degree) whereas degree_int() is for cases where the exponent should be an integer.

The difference between degree_int() and spline_degree() is the default ranges (which is based on the context of how/where they are used).

prod_degree() is used by parsnip::mars() for the number of terms in interactions (and generates an integer).

Examples

degree()
#> Polynomial Degree (quantitative)
#> Range: [1, 3]
degree_int()
#> Polynomial Degree (quantitative)
#> Range: [1, 3]
spline_degree()
#> Spline Degrees of Freedom (quantitative)
#> Range: [1, 10]
prod_degree()
#> Degree of Interaction (quantitative)
#> Range: [1, 2]