parsnip 0.1.6
Model Specification Changes
-
A new linear SVM model
svm_linear()
is now available with theLiblineaR
engine (#424) and thekernlab
engine (#438), and theLiblineaR
engine is available forlogistic_reg()
as well (#429). These models can use sparse matrices viafit_xy()
(#447) and have atidy
method (#474). -
For models with
glmnet
engines:- A single value is required for
penalty
(either a single numeric value or a value oftune()
) (#481). - A special argument called
path_values
can be used to set thelambda
path as a specific set of numbers (independent of the value ofpenalty
). A pure ridge regression models (i.e.,mixture = 1
) will generate incorrect values if the path does not include zero. See issue #431 for discussion (#486).
- A single value is required for
-
The
liquidSVM
engine forsvm_rbf()
was deprecated due to that package's removal from CRAN. (#425) -
The xgboost engine for boosted trees was translating
mtry
to xgboost'scolsample_bytree
. We now mapmtry
tocolsample_bynode
since that is more consistent with how random forest works.colsample_bytree
can still be optimized by passing it in as an engine argument.colsample_bynode
was added to xgboost after theparsnip
package code was written. (#495) -
For xgboost,
mtry
andcolsample_bytree
can be passed as integer counts or proportions, whilesubsample
andvalidation
should always be proportions.xgb_train()
now has a new optioncounts
(TRUE
orFALSE
) that states which scale formtry
andcolsample_bytree
is being used. (#461)
Other Changes
-
Re-licensed package from GPL-2 to MIT. See consent from copyright holders here.
-
set_mode()
now checks ifmode
is compatible with the model class, similar tonew_model_spec()
(@jtlandis, #467). Bothset_mode()
andset_engine()
now error forNULL
or missing arguments (#503). -
Re-organized model documentation for
update
methods (#479). -
generics::required_pkgs()
was extended forparsnip
objects. -
Prediction functions now give a consistent error when a user uses an unavailable value of
type
(#489) -
The
augment()
method was changed to avoid failing if the model does not enable class probabilities. The method now returns tibbles despite the input data class (#487) (#478) -
xgboost engines now respect the
event_level
option for predictions (#460).