# MachineShop News

## Version Updates

## 3.9.2

* Remove dead Rd links to the **ParBayesianOptimization** package.
* Set required java parameters in the `BARTMachineModel` example.

## 3.9.1

* Ensure that global settings are applied to compute nodes when `varimp()` runs in parallel.
* Compatibility fixes for `XGBModel` (`XGBDARTModel`, `XGBLinearModel`, `XGBTreeModel`).

## 3.9.0

* Add offset support to `XGBModel`.
* Add logical argument `pool` to `calibration()` indicating whether to compute a single calibration curve on predictions pooled over all resampling iterations or to compute them for each iteration individually and return the mean calibration curve.
  * The new argument default is `pool = FALSE`. The pooling that had been the only implementation in previous package versions (<= 3.8.0) can reproduced with `pool = FALSE` but is deprecated and will be removed along with the argument in a future version.
  * Note that pooling can result in large memory allocation errors when fitting smooth curves with `breaks = NULL`.

## 3.8.0

* Changes to `varimp()` arguments.
  * Add argument `sort`.
  * Extend argument `scale` to vectors of logical.
* Changes to model-based variable importance.
  * Fix unused argument error from `CForestModel`.
  * Use `drop1()` to compute model term-specific p-values for `CoxModel`, `POLRModel`, and `SurvRegModel` as is done for  `GLMModel` and `LMModel`.
* Changes to `VariableImportance` class.
  * Add slots `method` and `metric` to store the computational method (`"permute"` or `"model"`) and the performance metric used for computations.
  * Add `update()` method to add the new slots to objects created with previous versions of the package.
* Deprecate `type = "default"` option in `predict()` and replace it with `type = "raw"`.
* Fix unimplemented type 'list' in 'listgreater' error from `SelectedInput.recipe()`.

## 3.7.0

* Compatibility updates for **parsnip**.
* Enable resampling by a grouping variable with `BootControl`, `OOBControl`, and `SplitControl`.
* Enable resampling by a stratification variable with `SplitControl`.
* Require **R** 4.1.0 or later.

## 3.6.2

* Add backward compatibility for older `MLModel` objects without a `na.rm` slot.
* Fix CRAN check warning: S3 generic/method consistency.
* Update `role_binom()`, `role_case()`, and `role_surv()` to remove the requirement that their variables be present in `newdata` supplied to `predict()`.

## 3.6.1

* Compatibility updates for **ggplot2**, **Matrix**, and **recipes** package dependencies.

## 3.6.0

* Add argument `na.rm` to `MLModel()` for construction of a model that automatically removes all cases with missing values from model fitting and prediction, none, or only those whose missing values are in the response variable.  Set the `na.rm` values in supplied `MLModels` to automatically remove cases with missing values if not supported by their model fitting and prediction functions.
* Add argument `prob.model` to `SVMModel()`.
* Add argument `verbose` to `fit()` and `predict()`.
* Fix `Error in as.data.frame(x) : object 'x' not found` issue when fitting a `BARTMachineModel` that started occurring with `bartMachine` package version 1.2.7.
* Remove expired deprecations of `ModeledInput` and `rpp()`.
* Internal changes
  * Add slot `na.rm` to `MLModel`.

## 3.5.0

* Add argument `method` to `r2()` for calculation of Pearson or Spearman correlation.
* Add `predict()` S4 method for `MLModelFit`.
* Export `MLModelFunction()`.
* Export `as.MLInput()` methods for `MLModelFit` and `ModelSpecification`.
* Export `as.MLModel()` method for `ModelSpecification`.
* Improve recursive feature elimination of `SelectedInput` terms.
* Improve speed of `StackedModel` and `SuperModel`.
* Internal changes
  * Add `.MachineShop` list attribute to `MLModelFit`.
  * Move field `mlmodel` in `MLModelFit` to `model` in `.MachineShop`.
  * Move slot `input` in `MLModel` to `.MachineShop`.
  * Pass `.MachineShop` to the `predict` and `varimp` slot functions of `MLModel`.

## 3.4.3

* Fix `TypeError` in `dependence()` with numeric dummy variables from recipes.
* Prep `ModelRecipe` with `retain = TRUE` for recipe steps that are skipped, for example, when test datasets are created.
* Add generalized area under performance curves to `auc()`, `pr_auc()`, and `roc_auc()` for multiclass factor responses.

## 3.4.2

* Add argument `select` to `rfe()`.
* Fix object `perf_stats` not found in `optim()`.

## 3.4.1

* Add argument `conf` to `set_optim_bayes()`.
* Enable global grid expansion and tuning of `StackedModel` and `SuperModel` in `ModelSpecification()`.

## 3.4.0

* Fixes
  * Enable prediction with survival times of 0.
* Implement class `SelectedModelSpecification`.
* Internal changes
  * Deprecate classes `ModeledInput`, `ModeledFrame`, and `ModeledRecipe`.
  * Remove unused class `TunedModeledRecipe`.
* Expire deprecations
  * Remove argument `fixed` from `TunedModel()`.
  * Remove `Grid()`.
* Rename `rpp()` to `ppr()`.
* Replace `ModeledInput()` with `ModelSpecification()`.
* Require R >= 4.0.0.
* Use Olden algorithm for `NNetModel` model-specific variable importance.

## 3.3.1

* Fixes
  * `SurvRegModelFit` `summary()` error
  * update number of folds recorded in `CVControl` when stratification or grouping size leads to construction of fewer than requested folds for cross-validation resampling

## 3.3.0

* Add argument `.type` with options `"glance"` and `"tidy"` to `summary.MLModelFit()`.
* Add case components data (stratification and grouping variables) to `print.Resample()`.
* Add class and methods for `ModelSpecification`.
* Add training parameters set functions
  * `set_monitor()`: monitoring of resampling and optimization
  * `set_optim_bayes()`: Bayesian optimization with a Gaussian process model
  * `set_optim_bfgs()`: low-memory quasi-Newton BFGS optimization
  * `set_optim_grid()`: exhaustive and random grid searches
  * `set_optim_method()`: user-defined optimization functions
  * `set_optim_pso()`: particle swarm optimization
  * `set_optim_sann()`: simulated annealing
* Add `performance()` method for `MLModel` to replicate the previous behavior of `summary.MLModel()`.
* Add `performance()`, `plot()`, and `summary()` methods for `TrainingStep`.
* Add support for unordered plots of `Resample` performances.
* Changes to argument `type` of `predict()`.
  * Add option `"default"` for model-specific default predictions.
  * Add option `"numeric"` for numeric predictions.
  * Change option `"prob"` to be for probabilities between 0 and 1.
* Change `confusion()` default behavior to convert factor probabilities to levels.
* Rename argument `control` to `object` in set functions.
* Rename argument `f` to `fun` in `roc_index()`.
* Return a `ListOf` training step summaries from `summary.MLModel()`.
* Return a `TrainingStep` object from `rfe()`.
* Support tibble-convertible objects as arguments to `expand_params()`.
* Internal changes
  * Add class `EnsembleModel`.
  * Add classes `MLOptimization`, `GridSearch`, `NullOptimization`, `RandomGridSearch`, and `SequentialOptimization`.
  * Add class `NullControl`.
  * Add slot `control` to `PerformanceCurve`.
  * Add slot `method` to `TrainingStep`.
  * Add slot `optim` to `TrainingParams`.
  * Add slot `params` to `MLInput`.
  * Inherit class `SelectedModel` from `EnsembleModel`.
  * Inherit class `StackedModel` from `EnsembleModel`.
  * Inherit class `SuperModel` from `StackedModel`.
  * Rename slot `case_comps` to `vars` in `Resample`.
  * Rename slot `grid` to `log` in `TrainingStep`.
* Fixes
  * error predicting single factor response in `GLMModel`
  * 'size(x@performance, 3)' error in `print.TrainingStep()`
  * 'Unmatched tuning parameters' error in `TunedModel()`

## 3.2.1

* Fix 'data' argument of wrong type error in `terms.formula()`.
* Require >= 3.1.0 version of **cli** package.

## 3.2.0

* Add argument `distr` and `method` to `dependence()`.
* Add function `ParsnipModel()` for model specifications (`model_spec`) from the [**parsnip**](https://parsnip.tidymodels.org/) package.
* Add function `rfe()` for recursive feature elimination.
* Add method `as.MLModel()` for `model_spec` and `ModeledInput`.
* Add support for any model specification whose object has an `as.MLModel()` method.
* Add support for cross-validation with case groups.
* Add support for names in argument `metric` of `auc()`.
* Change argument `method` default from `"model"` to `"permute"` in `varimp()`.
* Change class `ModelFrame` to an S4 class; generally requires explicit conversion to a data frame with `as.data.frame()` in `MLModel` `fit` and `predict` functions.
* Change progress bar display from elapsed to estimated completion time.
* Changes to global settings
  * Rename `stat.Trained` to `stat.TrainingParams`.
  * Remove `stats.VarImp`.
* Changes to internal classes
  * Add class `ParsnipModel`.
  * Add class `SurvTimes`.
  * Add class `TrainingParams`.
  * Add class union `Grid`.
  * Add class union `Params`.
  * Add column `name`, `selected`, and `metrics` to slot `grid` of `TrainingStep` class.
  * Add slot `grid` to `TunedInput`.
  * Add slot `id` to `MLInput` and `MLModel` classes.
  * Add slot `id` and `name` to `TrainingStep` class.
  * Add slot `models` to `SelectedModel`.
  * Remove slot `name` from `MLControl` classes.
  * Remove slot `selected`, `values`, and `metric` from `TrainingStep` class.
  * Remove slot `shift` from `VariableImportance` class.
  * Rename class `Grid` to `TuningGrid`.
  * Rename class `Resamples` to `Resample`.
  * Rename class `TrainStep` to `TrainingStep`.
  * Rename class `VarImp` to `VariableImportance`.
  * Rename classes of `MLControl`.
    * `MLBootControl` &rarr; `BootControl`
    * `MLBootOptimismControl` &rarr; `BootOptimismControl`
    * `MLCVControl` &rarr; `CVControl`
    * `MLCVOptimismControl` &rarr; `CVOptimismControl`
    * `MLOOBControl` &rarr; `OOBControl`
    * `MLSplitControl` &rarr; `SplitControl`
    * `MLTrainControl` &rarr; `TrainControl`
  * Rename column `Input` and `Model` to `params` in slot `grid` of `TrainingStep` class.
  * Rename column `Resample` to `Iteration` in `Resample` class
  * Rename slot `x` to `input` in `MLModel` class.
* Changes to `XGBModel`
  * Change argument default for `nrounds` from 1 to 100.
  * Rearrange constructor arguments.
  * Reduce number of tuning grid parameters
    * Include `nrounds` and `max_depth` in automated grids for `XGBDARTModel` and `XGBTreeModel`.
    * Include `nrounds`, `lambda`, and `alpha` in automated grid for `XGBLinearModel`.
  * Compute survival probabilities for `survival:aft` prediction.
  * Change default survival objective from `survival:cox` to `survival:aft`.
* Format and condense printout of objects.
* Include all computed performance metrics in `TrainingStep` objects and output.
* Remove shift from variable importance scaling in `varimp()`.
* Rename and redefine dispatch (first) arguments in functions.
  * `model` &rarr; `object` in `TunedModel()`
  * `x` &rarr; `object` in `expand_model()`
  * `x` &rarr; `formula`/`input`/`model` in `expand_modelgrid()`, `fit()`, `ModelFrame()`, `resample()`, `rfe()` methods
  * `x` &rarr; `formula`/`object`/`model` in `ModeledInput()` methods
  * `x` &rarr; `object` in `ParameterGrid()` methods
  * `x` &rarr; `control` in `set_monitor()`, `set_predict()`, `set_strata()`
  * `x` &rarr; `object` in `TunedInput()`
* Rename function `Grid()` to `TuningGrid()`.
* Reorder optional arguments in `ModelFrame()`.
* Save model constructor arguments as the list elements in `MLModel` `params` slots.

## 3.1.0

* Add argument `na.rm` to `dependence()`.
* Add global setting `stats.VarImp` for summary statistics to compute on permutation-based variable importance.
* Add permutation-based variable importance to `varimp()`.
* Sort variable importance by first column only if not scaled.
* Correct the estimated variances for cross-validation estimators of mean performance difference in `t.test.PerformanceDiff()`.
* Rename argument `metric` to `type` in `varimp()` functions for `BartMachineModel`, `C50Model`,  `EarthModel`,  `RFSRCModel`, and `XGBModel`.
* Set argument `type` default to `"nsubsets"` in `EarthModel` `varimp()`.
* Expand case weighted metrics support.
  * Fix weights used in survival event-specific metrics.
  * Use weights for `cross_entropy()` `numeric` method.
  * Use weights for predicted survival probabilities.
* Fix error with argument `f` in `roc_index()` `Surv` method.

## 3.0.0

* Add slot `weights` to `MLModel` classes.
* Allow case weights in `LMModel` for all response types.
* Exclude infinite values from calculation of `breaks` in `calibration()`.
* Fix invalid `max = Inf` arguments to `print.default()`.
* Add support for case weights in performance metrics and curves.
* Evaluate `ModelFrame()` arguments `strata` and `weights` in `data` environment.
* Fix issue introduced in package version 2.9.0 of recipe case weights not being used in model fitting.
* Add column `Weight` of case weights to `Resamples` data frame.
* Rename `values` column to `get_values` in `MLModel` `gridinfo` slot.
* Move global settings `resample_progress` and `resample_verbose` to `set_monitor()` arguments `progress` and `verbose`.
* Move `MLControl()` arguments `strata_breaks`, `strata_nunique`, `strata_prop`, and `strata_size` to `set_strata()` arguments `breaks`, `nunique`, `prop`, and `size`.
* Move `MLControl()` arguments `times`, `distr`, and `method` to `set_predict()`.
* Export `%>%` operator.
* Return case stratification values in the 'strata' slot of `Resamples` objects.

## 2.9.0

* Rename tibble column `regular` to `default` in `MLModel` gridinfo slot.
* Redefine `size` and `random` arguments of `ParameterGrid()` to match those of `Grid()`.
* Revise selection of character values in model grids.
  * Select `coeflearn` values in their defined order instead of at random in `AdaBoostModel`.
  * Select `kernels` values in their defined order instead of at random in `KNNModel`.
  * Add survival `splitrule` methods in `RangerModel`.
  * Select `splitrule` values in their defined order instead of at random in `RangerModel`.
* Revise global settings names.
  * Rename `max.print` to `print_max`.
  * Rename `progress.resample` to `resample_progress`.
  * Rename `stat.train` to `stat.Trained`.
  * Rename `dist.Surv` to `distr.SurvMeans`.
  * Rename `dist.SurvProbs` to `distr.SurvProbs`.
* Implement customized stratification methods for resampling.
  * Stratify survival data by time within event status by default instead of by event status only.
  * Add `strata_breaks`, `strata_nunique`, `strata_prop` and `strata_size` arguments to `MLControl()` constructor.
  * Reduce `strata_breaks` if numeric quantile bins are below `strata_prop` and `strata_size`.
  * Pool smallest factor levels below `strata_prop` and `strata_size` iteratively.
  * Pool smallest adjacent ordered levels below `strata_prop` and `strata_size` iteratively.
* Remove deprecated `length` arguments from `Grid()` and `ParameterGrid()`.
* Drop compatibility with deprecated `gridinfo` functions in `MLModel()`.
* New and improved survival analysis methods.
  * Add support for counting process survival data.
  * Use model weights in estimation of predicted baseline survival curves.
  * Change censoring curve estimation method from direct to cumulative hazard-based in the `brier()` metric.
  * Improve computational speed of survival curve estimation.
  * Remove `"fleming-harrington"` as a choice for the `method` argument of `predict()` and for the `method.EmpiricalSurv` global setting, because it is a special case of the existing (default) `"efron"` choice and thus not needed.
  * Add `"rayleigh"` choice for the `distr.Surv` and `distr.SurvProbs` global settings.
* Rename `dist` argument to `distr` in `calibration()`, `MLControl()`, `predict()`, and `r2()`.
* Return survival distribution name with predicted values.
  * Add `distr` argument to `SurvEvents()` and `SurvProbs()`.
  * Add `SurvMeans` class.
  * Return predicted mean survival times as `SurvMeans` object.
  * Default to the distribution used in predicting mean survival times in `calibration()` and `r2()`.
* Rename `"terms"` predictor_encoding to `"model.frame"` in `MLModel` class.
* Pass elliptical arguments in `performance()` response type-specific methods to `metrics` supplied as a single `MLMetric` function.

## 2.8.0

* Replace `get_grid()` with `expand_modelgrid()`.
* Fix for truncated grid of lambda values in `GLMNetModel`.
* Support package version constraints in `MLModel`.

## 2.7.1

* Rename `traininfo` slot to `train_steps` in `MLModel` classes.
* Issue #4: compatibility fix for **recipes** package change in behavior of the `retain` argument in `prep()`.

## 2.7.0

* Sort randomly sampled grid points.
* Change `fixed` argument default `NULL` to `list()` in `TunedModel()`.
* CRAN release.

## 2.6.2

* Rename `length` argument to `size` in `Grid()` and `ParameterGrid()`.
* Add support for named sizes in `ParameterGrid()`.
* Revise model tuning grids.
  * Replace `grid` slot with `gridinfo` in `MLModel` classes.
  * Add support for size vectors in `Grid()`.
  * Add `get_grid()` function to extract model-defined tuning grids.
* Rename `trainbits` slot to `traininfo` in `MLModel` classes.

## 2.6.1

* Doc edits: do not test examples requiring suggested packages.
* CRAN release.

## 2.6.0

* Preprocess data for automated grid construction only when needed.
* Select `RPartModel` `cp` grid points from `cptable` according to smallest cross-validation error (mean plus one standard deviation).
* CRAN release.

## 2.5.2

* Export `Performance` `diff()` method.

## 2.5.1

* Implement fast random forest model `RFSRCModel`.
* Export `unMLModelFit()` function to revert an `MLModelFit` object to its original class.

## 2.5.0

* Add `options` argument to `step_lincomp()` and `step_sbf()`.
* CRAN release.

## 2.4.3

* Add recipe `step_sbf()` function for variable selection by filtering.
* Inherit `step_kmedoids` objects from `step_sbf`, and refactor methods.
  * Support user-specified center and scale functions.
  * Append prefix to selected variable names.
  * Rename `tidy()` column `medoids` to `selected`.
  * Rename `tidy()` column `names` to `name`.
  * Set `tidy()` non-selected variable names to `NA`.
* Add recipe `step_lincomp()` function for linear components variable reduction.
* Inherit `step_kmeans` objects from `step_lincomp`, and refactor methods.
  * Support user-specified center and scale functions.
  * Rename `tidy()` column `names` to `name`.
* Inherit `step_spca` objects from `step_lincomp`, and refactor methods.
  * Support user-specified center and scale functions.
  * Rename `tidy()` column `value` to `weight`.
  * Rename `tidy()` column `component` to `name`.
* Set `GBMModel` distribution to bernoulli, instead of multinomial, for binary responses.

## 2.4.2

* Add global setting `RHS.formula` for listing of operators and functions allowed on right-hand side of traditional formulas.
* Add clara clustering method to `step_kmedoids()`.
* Support Cox and accelerated failure time regression for survival responses in `XGBModel`, `XGBDARTModel`, `XGBLinearModel`, and `XGBTreeModel`.

## 2.4.1

* Set `NNetModel` `linout` argument automatically according to the response variable type (numeric: `TRUE`, other: `FALSE`).  Previously, `linout` had a default value of `FALSE` as defined in the `nnet` package.

## 2.4.0

* CRAN release.

## 2.3.2

* Display progress bars for sequential resampling iterations.

## 2.3.1

* R 4.0 data.frame compatibility updates for calibration curves.
* Fix recipe prediction with StackedModel and SuperModel

## 2.3.0

* Display progress messages for any foreach parallel backend.

## 2.2.5

* Show all error messages when resample selection stops.
* Preserve predictor names in `NNetModel` `fit()` method.
* Fix aggregation of performance curves with infinite values.
* Add progress bar and verbose output options for `resample()` methods.
* Get non-negative probabilities for survival confusion matrix.
* Update Using webpages and vignette.

## 2.2.4

* Fix `BARTMachineModel` to predict highest binary response level.
* Grid tune `BARTMachineModel` `nu` parameter for numeric responses only.

## 2.2.3

* Extend `ModeledInput()` to `SelectedModelFrame`, `SelectedModelRecipe`, and `TunedModelRecipe`.

## 2.2.2

* Fix updating of recipe parameters in `TunedInput()`.

## 2.2.1

* Print `StackedModel` and `SuperModel` training information.
* Fix missing case names when resampling with recipes.

## 2.2.0

* CRAN release.

## 2.1.4

* Add cost-complexity pruning parameters to `TreeModel`.
* Perform stratified resampling automatically for `ModeledInput()` and `SelectedInput()` objects constructed with formulas and matrices.

## 2.1.3

* Revisions needed to some `fit()` methods to ensure that unprepped recipes are passed to models, like `TunedModed`, `StackedModel`, `SelectedModel` and `SuperModel`, needing to replicate preprocessing steps in their resampling routines.
* Extend `GLMModel` to factor and matrix responses.
* Use `fun` instead of deprecated `fun.y` in ggplot2 functions.
* Capture user-supplied parameters passed in to the ellipsis of model constructor functions that have them.

## 2.1.2

* Compatibility fix for tibble 3.0.0.
* Include missing values in model matrices created internally from formulas.

## 2.1.1

* Improve specificity of `metricinfo()` results for factor responses.
* Correct `SplitControl()` to train on the split sample instead of the full dataset.
* Perform stratified resampling automatically when `fit()` formula and matrix methods are called with meta-models.

## 2.1.0

* CRAN release.

## 2.0.4

* Extend `print()` argument `n` to data frame and matrix columns for more concise display of large data structures.
* Add preprocessing recipe functions `step_kmeans()`, `step_kmedoids()`, and `step_spca()`.

## 2.0.3

* Internal changes:
  * Remove `MLModel` slot `y`.
  * Rename `ModelFrame` and `ModelRecipe` columns `(casenames)` to `(names)`.
  * Register `ModelFrame` inheritance from `data.frame`.
  * Define `Terms` S4 classes for `ModelFrame` slot `terms`.

## 2.0.2

* Implement `ModeledInput`, `SelectedInput` and `TunedInput` classes and methods.
* Deprecate `SelectedFormula()`, `SelectedMatrix()`, `SelectedModelFrame()`, `SelectedRecipe()`, and `TunedRecipe()`.
* Remove deprecated `tune()`.
* Rename global setting `stat.Curves` to `stat.Curve`.

## 2.0.1

* Rename global setting `stat.Train` to `stat.train`.
* Add print methods for `SelectedModel`, `StackedModel`, `SuperModel`, and `TunedModel`.
* Revise training methods to ensure nested resampling of `SelectedRecipe` and `TunedRecipe`.
* Return list of all training steps in `MLModel` `trainbits` slot.

## 2.0.0

* Rename global setting `stat.Tune` to `stat.Train`.
* Enable selection of formulas, design matrices, and model frames with `SelectedFormula()`, `SelectedMatrix()`, and `SelectedModelFrame()`.
* Rename discrete variable classes: `BinomialMatrix` &rarr; `BinomialVariate`, `DiscreteVector` &rarr; `DiscreteVariate`, `NegBinomialVector` &rarr; `NegBinomialVariate`, and `PoissonVector` &rarr; `PoissonVariate`.
* Add global setting `require` for user-specified packages to load during parallel execution of resampling algorithms.
* Rename recipe role `case_strata` to `case_stratum`.
* Rename `object` argument to `data` in `ConfusionMatrix()`, `SurvEvents()`, and `SurvProbs()`.
* Add `c` methods for `BinomialVariate`, `DiscreteVariate`, `ListOf`, and `SurvMatrix`.
* Add `role_binom()`, `role_case()`, `role_surv()`, and `role_term()` to set recipe roles.
* Support `base` argument to `varimp()` for log-transformed p-values.
* Rename `ParamSet` to `ParameterGrid`.
* Add option to `reset` global settings individually.
* Add `as.data.frame` methods for `Performance`, `Performance` summary, `PerformanceDiff`, `PerformanceDiffTest`, and `Resamples`.

## 1.99.0

* Implement `DiscreteVector` class and subclasses `BinomialVector`, `NegBinomialVector`, and `PoissonVector` for discrete response variables.
* Extend model support to `DiscreteVector` classes as follows.
  * `DiscreteVector`: all models applicable to numeric responses.
  * `BinomialVector`/`NegBinomialVector`/`PoissonVector`: `BlackBoostModel`, `GAMBoostModel`, `GLMBoostModel`, `GLMModel`, and `GLMStepAICModel`.
  * `BinomialVector`/`PoissonVector`: `GLMNetModel`.
  * `PoissonVector`: `GBMModel` and `XGBModel`
* Add support for offset terms in formulas, model matrices, and recipes.
* Add recipe tune information to fitted `MLModel`.
* Replace `Calibration()`, `Confusion()`, `Curves()`, `Lift()`, and `Resamples()` with `c` methods.
* Redefine `Confusion` S3 class as `ConfusionList` S4 class.
* Remove support for one-element list to `metricinfo()` and `modelinfo()`.
* Remove deprecated `expand.model()`.
* Expire deprecated `tune()`.

## 1.6.4

* Calculate regression variable importance as negative log p-values.
* Support empty vectors in `metricinfo()` and `modelinfo()`.
* Add support for **dials** package parameter sets with `ParamSet()`.

## 1.6.3

* Add `as.MLModel()` for coercing `MLModelFit` to `MLModel`.
* Deprecate `tune()`; call `fit()` with a `SelectedModel` or `TunedModel` instead.

## 1.6.2

* Implement optimism-corrected cross-validation (`CVOptimismControl`).
* Fix `BootOptimismControl` error with 2D responses.
* Add global option `max.print` for the number of models and data frame rows to show with print methods.
* Enable recipe selection with `SelectedRecipe()`.
* Refactor `tune()` methods.
* Replace `MLModelFit` element `fitbits` (`MLFitBits` object) with `mlmodel` (`MLModel` object).
* Rename `VarImp` slot `center` to `shift`.

## 1.6.1

* Use tibbles for parameter grids.
* Add random sampling option to `expand_model()`, `expand_params()`, and `expand_steps()`.
* Display information for model functions and objects more compactly.

## 1.6.0

* Add global setting for default cutoff threshold value.
* Add option to reset all global settings.
* Enable recipe tuning with `TunedRecipe()`.
* Add `expand_model()` for model expansion over tuning parameters.
* Add `expand_params()` for model parameters expansion.
* Add `expand_steps()` for recipe step parameters expansion.
* Implement `MLModelFunction` and `MLModelList` classes.
* Add fit methods for `MLModel`, `MLModelFunction`, and `MLModelList`.
* Fix `NNetModel` fit error with binary and factor responses.
* Fix `modelinfo()` function not found error.

## 1.5.2

* Implement exception handling of `tune()` resampling failures.
* Remove deprecated `types` and `design` arguments from `MLModel()`.

## 1.5.1

* Implement global settings for default resampling control, performance metrics, summary statistics, and tuning grid.
* Support vector arguments in `metricinfo()` and `modelinfo()`.
* Update package documentation.

## 1.5.0

* Implement model: `SelectedModel`.
* Remove `maximize` argument from `tune()` and `TunedModel`.
* Support lists as arguments to `StackedModel()` and `SuperModel`.

## 1.4.2

* Revert renaming of `expand.model()`.
* Exclude 0 distance from `KNNModel` tuning grid.
* Improve random tuning grid coverage.

## 1.4.1

* Implement model: `TunedModel`.
* Remove deprecated `na.action` argument from `ModelFrame` methods.
* Rename `MLModel()` argument `types` to `response_types`.
* Rename `MLModel()` argument `design` to `predictor_encoding`.
* Rename `expand.model()` to `expand_model()`.

## 1.4.0

* CRAN release.

## 1.3.3

* Implement optimism-corrected bootstrap resampling (`BootOptimismControl`).
* Store case names in `ModelFrame` and `ModelRecipe` and save to `Resamples`.

## 1.3.2

* Add `BinaryConfusionMatrix` and `OrderedConfusionMatrix` classes.
* Export `ConfusionMatrix` constructor.
* Extend `metricinfo()` to confusion matrices.
* Refactor performance metrics methods code.

## 1.3.1

* Check and convert ordered factors in response methods.
* Check consistency of extracted variables in response methods.
* Add metrics methods for `Resamples`.

## 1.3.0

* Improve compatibility with preprocessing recipes.
* Allow base math functions and operators in `ModelFrame` formulas.

## 1.2.5

* Save `ModelFrame` response in first column.
* Unexport `response` formula method.
* Add `ICHomes` dataset.
* Add `center` and `scale` slot to `VarImp`.

## 1.2.4

* Prohibit in-line functions in `ModelFrame` formulas.
* Rename `response` function argument from `data` to `newdata`.

## 1.2.3

* Add `fit`, `resample`, and `tune` methods for design matrices.
* Reduce computational overhead for design matrices and recipes.
* Rename `ModelFrame()` argument `na.action` to `na.rm`.

## 1.2.2

* Implement parametric (``"exponential"``, ``"rayleigh"``, ``"weibull"``) estimation of baseline survival functions.
* Set ``"weibull"`` as the default distribution for survival mean estimation.
* Add extract method for ``Resamples``.
* Add ``na.rm`` argument to ``calibration()``, ``confusion()``, ``performance()``, and ``performance_curve()``.
* Add loess ``span`` argument to ``calibration()``.
* Change ``SurvMatrix`` from S4 to S3 class.

## 1.2.1

* Add ``method`` option to ``predict()`` for Breslow, Efron (default), or Fleming-Harrington estimation of survival curves for Cox proportional hazards-based models.
* Add ``dist`` option to ``predict()`` for exponential or Weibull approximation to estimated survival curves.
* Add ``dist`` option to ``calibration()`` for distributional estimation of observed mean survival.
* Add ``dist`` option to ``r2()`` for distributional estimation of the total sum of squares mean.
* Handle unnamed arguments in ``metricinfo()`` and ``modelinfo()``.

## 1.2.0

* Implement metrics: ``auc``, ``fnr``, ``fpr``, ``rpp``, ``tnr``, ``tpr``.
* Implement performance curves, including ROC and precision recall.
* Implement ``SurvMatrix`` classes for predicted survival events and probabilities to eliminate need for separate ``times`` arguments in calibration, confusion, metrics, and performance functions.
* Add calibration curves for predicted survival means.
* Add lift curves for predicted survival probabilities.
* Add recipe support for survival and matrix outcomes.
* Rename ``MLControl`` argument ``surv_times`` to ``times``.
* Fix identification of recipe ``case_weight`` and ``case_strata`` variables.
* Launch package [website](https://brian-j-smith.github.io/MachineShop/).
* Bring Introduction vignette up to date with package features.

## 1.1.0

* Implement model: ``BARTModel``.
* Implement model tuning over automatically generated grids of parameter values and random sampling of grid points.
* Add metrics for predicted survival times: ``accuracy``, ``f_score``, ``kappa2``, ``npv``, ``ppv``, ``pr_auc``, ``precision``, ``recall``, ``roc_index``, ``sensitivity``, ``specificity``
* Add metrics for predicted survival means: ``cindex``, ``gini``, ``mae``, ``mse``, ``msle``, ``r2``, ``rmse``, ``rmsle``.
* Add ``performance`` and metric methods for ``ConfusionMatrix``.
* Add confusion matrices for predicted survival times.
* Standardize predict functions to return mean survival when times are not specified.
* Replace ``MLModel`` slot and constructor argument ``nvars`` with ``design``.

## 1.0.0

* Implement models: ``BARTMachineModel``, ``LARSModel``.
* Implement performance metrics: ``gini``, multi-class ``pr_auc`` and ``roc_auc``, multivariate ``rmse``, ``msle``, ``rmsle``.
* Implement smooth calibration curves.
* Implement ``MLMetric`` class for performance metrics.
* Add ``as.data.frame`` method for ``ModelFrame``.
* Add ``expand.model`` function.
* Add ``label`` slot to ``MLModel``.
* Expand ``metricinfo/modelinfo`` support for mixed argument types.
* Rename ``calibration`` argument ``n`` to ``breaks``.
* Rename ``modelmetrics`` function to ``performance``.
* Rename ``ModelMetrics/Diff`` classes to ``Performance/Diff``.
* Change ``MLModelTune`` slot ``resamples`` to ``performance``.

## 0.4.0

* Implement models: ``AdaBagModel``, ``AdaBoostModel``, ``BlackBoostModel``, ``EarthModel``, ``FDAModel``, ``GAMBoostModel``, ``GLMBoostModel``, ``MDAModel``, ``NaiveBayesModel``, ``PDAModel``, ``RangerModel``, ``RPartModel``, ``TreeModel``
* Implement user-specified performance metrics in ``modelmetrics`` function.
* Implement metrics: ``accuracy``, ``brier``, ``cindex``, ``cross_entropy``, ``f_score``, ``kappa2``, ``mae``, ``mse``, ``npv``, ``ppv``, ``pr_auc``, ``precision``, ``r2``, ``recall``, ``roc_auc``, ``roc_index``, ``sensitivity``, ``specificity``, ``weighted_kappa2``.
* Add ``cutoff`` argument to ``confusion`` function.
* Add ``modelinfo`` and ``metricinfo`` functions.
* Add ``modelmetrics`` method for ``Resamples``.
* Add ``ModelMetrics`` class with ``print`` and ``summary`` methods.
* Add ``response`` method for ``recipe``.
* Export ``Calibration`` constructor.
* Export ``Confusion`` constructor.
* Export ``Lift`` constructor.
* Extend ``calibration`` arguments to observed and predicted responses.
* Extend ``confusion`` arguments to observed and predicted responses.
* Extend ``lift`` arguments to observed and predicted responses.
* Extend ``metrics`` and ``stats`` function arguments to accept function names.
* Extend ``Resamples`` to arguments with multiple models.
* Change ``CoxModel``, ``GLMModel``, and ``SurvRegModel`` constructor definitions so that model control parameters are specified directly instead of with a separate ``control`` argument/structure.
* Change ``predict(..., times = numeric())`` function calls to survival model fits to return predicted values in the same direction as survival times.
* Change ``predict(..., times = numeric())`` function calls to ``CForestModel`` fits to return predicted means instead of medians.
* Change ``tune`` function argument ``metrics`` to be defined in terms of a user-specified metric or metrics.
* Deprecate MLControl arguments ``cutoff``, ``cutoff_index``, ``na.rm``, and ``summary``.

## 0.3.0

* Implement linear models (``LMModel``), linear discriminant analysis (``LDAModel``), and quadratic discriminant analysis (``QDAModel``).
* Implement confusion matrices.
* Support matrix response variables.
* Support user-specified stratification variables for resampling via the ``strata`` argument of ``ModelFrame`` or the role of ``"case_strata"`` for recipe variables.
* Support user-specified case weights for model fitting via the role of ``"case_weight"`` for recipe variables.
* Provide fallback for models with undefined variable importance.
* Update the importing of ``prepper`` due to its relocation from ``rsample`` to ``recipes``.

## 0.2.0

* Implement partial dependence, calibration, and lift estimation and plotting.
* Implement k-nearest neighbors model (``KNNModel``), stacked regression models (``StackedModel``), super learner models (``SuperModel``), and extreme gradient boosting (``XGBModel``).
* Implement resampling constructors for training resubstitution (``TrainControl``) and split training and test sets (``SplitControl``).
* Implement ``ModelFrame`` class for general model formula and dataset specification.
* Add multi-class Brier score to ``modelmetrics()``.
* Extend ``predict()`` to automatically preprocess recipes and to use training data as the ``newdata`` default.
* Extend ``tune()`` to lists of models.
* Extent ``summary()`` argument ``stats`` to functions.
* Fix survival probability calculations in ``GBMModel`` and ``GLMNetModel``.
* Change ``MLControl`` argument ``na.rm`` default from ``FALSE`` to ``TRUE``.
* Removed ``na.rm`` argument from ``modelmetrics()``.

## 0.1

* Initial public release
