extract-parsnip {parsnip} | R Documentation |
Extract elements of a parsnip model object
Description
These functions extract various elements from a parsnip object. If they do not exist yet, an error is thrown.
-
extract_spec_parsnip()
returns the parsnip model specification. -
extract_fit_engine()
returns the engine specific fit embedded within a parsnip model fit. For example, when usinglinear_reg()
with the"lm"
engine, this returns the underlyinglm
object. -
extract_parameter_dials()
returns a single dials parameter object. -
extract_parameter_set_dials()
returns a set of dials parameter objects.
Usage
## S3 method for class 'model_fit'
extract_spec_parsnip(x, ...)
## S3 method for class 'model_fit'
extract_fit_engine(x, ...)
## S3 method for class 'model_spec'
extract_parameter_set_dials(x, ...)
## S3 method for class 'model_spec'
extract_parameter_dials(x, parameter, ...)
Arguments
x |
A parsnip |
... |
Not currently used. |
parameter |
A single string for the parameter ID. |
Details
Extracting the underlying engine fit can be helpful for describing the
model (via print()
, summary()
, plot()
, etc.) or for variable
importance/explainers.
However, users should not invoke the predict()
method on an extracted
model. There may be preprocessing operations that parsnip
has executed on
the data prior to giving it to the model. Bypassing these can lead to errors
or silently generating incorrect predictions.
Good:
parsnip_fit %>% predict(new_data)
Bad:
parsnip_fit %>% extract_fit_engine() %>% predict(new_data)
Value
The extracted value from the parsnip object, x
, as described in the description
section.
Examples
lm_spec <- linear_reg() %>% set_engine("lm")
lm_fit <- fit(lm_spec, mpg ~ ., data = mtcars)
lm_spec
extract_spec_parsnip(lm_fit)
extract_fit_engine(lm_fit)
lm(mpg ~ ., data = mtcars)