Type: | Package |
Title: | Fast Machine Learning Model Training and Evaluation |
Version: | 0.6.1 |
Description: | Streamlines the training, evaluation, and comparison of multiple machine learning models with minimal code by providing comprehensive data preprocessing and support for a wide range of algorithms with hyperparameter tuning. It offers performance metrics and visualization tools to facilitate efficient and effective machine learning workflows. |
Encoding: | UTF-8 |
License: | MIT + file LICENSE |
URL: | https://github.com/selcukorkmaz/fastml |
BugReports: | https://github.com/selcukorkmaz/fastml/issues |
LazyData: | true |
Imports: | recipes, dplyr, ggplot2, reshape2, rsample, parsnip, tune, workflows, yardstick, tibble, rlang, dials, RColorBrewer, baguette, bonsai, discrim, doFuture, finetune, future, plsmod, probably, viridisLite, DALEX, magrittr, patchwork, pROC, janitor, stringr, DT, GGally, UpSetR, VIM, broom, dbscan, ggpubr, gridExtra, htmlwidgets, kableExtra, moments, naniar, plotly, scales, skimr, tidyr, knitr, rmarkdown, purrr, mice, missForest |
Suggests: | testthat (≥ 3.0.0), C50, glmnet, xgboost, ranger, crayon, kernlab, klaR, kknn, keras, lightgbm, rstanarm, mixOmics, |
RoxygenNote: | 7.3.2 |
Config/testthat/edition: | 3 |
NeedsCompilation: | no |
Packaged: | 2025-06-10 22:04:39 UTC; selcukkorkmaz |
Author: | Selcuk Korkmaz |
Maintainer: | Selcuk Korkmaz <selcukorkmaz@gmail.com> |
Depends: | R (≥ 3.5.0) |
Repository: | CRAN |
Date/Publication: | 2025-06-10 22:50:02 UTC |
Get Available Methods
Description
Returns a character vector of algorithm names available for either classification or regression tasks.
Usage
availableMethods(type = c("classification", "regression"), ...)
Arguments
type |
A character string specifying the type of task. Must be either |
... |
Additional arguments (currently not used). |
Details
Depending on the specified type
, the function returns a different set of algorithm names:
For
"classification"
, it returns algorithms such as"logistic_reg"
,"multinom_reg"
,"decision_tree"
,"C5_rules"
,"rand_forest"
,"xgboost"
,"lightgbm"
,"svm_linear"
,"svm_rbf"
,"nearest_neighbor"
,"naive_Bayes"
,"mlp"
,"discrim_linear"
,"discrim_quad"
, and"bag_tree"
.For
"regression"
, it returns algorithms such as"linear_reg"
,"ridge_regression"
,"lasso_regression"
,"elastic_net"
,"decision_tree"
,"rand_forest"
,"xgboost"
,"lightgbm"
,"svm_linear"
,"svm_rbf"
,"nearest_neighbor"
,"mlp"
,"pls"
, and"bayes_glm"
.
Value
A character vector containing the names of the available algorithms for the specified task type.
Evaluate Models Function
Description
Evaluates the trained models on the test data and computes performance metrics.
Usage
evaluate_models(
models,
train_data,
test_data,
label,
task,
metric = NULL,
event_class
)
Arguments
models |
A list of trained model objects. |
train_data |
Preprocessed training data frame. |
test_data |
Preprocessed test data frame. |
label |
Name of the target variable. |
task |
Type of task: "classification" or "regression". |
metric |
The performance metric to optimize (e.g., "accuracy", "rmse"). |
event_class |
A single string. Either "first" or "second" to specify which level of truth to consider as the "event". |
Value
A list with two elements:
- performance
A named list of performance metric tibbles for each model.
- predictions
A named list of data frames with columns including truth, predictions, and probabilities per model.
FastExplain the fastml (DALEX + SHAP + Permutation-based VI)
Description
Provides model explainability using DALEX. This function:
Creates a DALEX explainer.
Computes permutation-based variable importance with boxplots showing variability, displays the table and plot.
Computes partial dependence-like model profiles if 'features' are provided.
Computes Shapley values (SHAP) for a sample of the training observations, displays the SHAP table, and plots a summary bar chart of
\text{mean}(\vert \text{SHAP value} \vert)
per feature. For classification, it shows separate bars for each class.
Usage
fastexplain(
object,
method = "dalex",
features = NULL,
grid_size = 20,
shap_sample = 5,
vi_iterations = 10,
seed = 123,
loss_function = NULL,
...
)
Arguments
object |
A |
method |
Currently only |
features |
Character vector of feature names for partial dependence (model profiles). Default NULL. |
grid_size |
Number of grid points for partial dependence. Default 20. |
shap_sample |
Integer number of observations from processed training data to compute SHAP values for. Default 5. |
vi_iterations |
Integer. Number of permutations for variable importance (B). Default 10. |
seed |
Integer. A value specifying the random seed. |
loss_function |
Function. The loss function for
|
... |
Additional arguments (not currently used). |
Details
-
Custom number of permutations for VI (vi_iterations):
You can now specify how many permutations (B) to use for permutation-based variable importance. More permutations yield more stable estimates but take longer.
-
Better error messages and checks:
Improved checks and messages if certain packages or conditions are not met.
-
Loss Function:
A
loss_function
argument has been added to let you pick a different performance measure (e.g.,loss_cross_entropy
for classification,loss_root_mean_square
for regression). -
Parallelization Suggestion:
Value
Prints DALEX explanations: variable importance table & plot, model profiles (if any), and SHAP table & summary plot.
Explore and Summarize a Dataset Quickly
Description
fastexplore
provides a fast and comprehensive exploratory data analysis (EDA) workflow.
It automatically detects variable types, checks for missing and duplicated data,
suggests potential ID columns, and provides a variety of plots (histograms, boxplots,
scatterplots, correlation heatmaps, etc.). It also includes optional outlier detection,
normality testing, and feature engineering.
Usage
fastexplore(
data,
label = NULL,
visualize = c("histogram", "boxplot", "barplot", "heatmap", "scatterplot"),
save_results = TRUE,
output_dir = NULL,
sample_size = NULL,
interactive = FALSE,
corr_threshold = 0.9,
auto_convert_numeric = TRUE,
visualize_missing = TRUE,
imputation_suggestions = FALSE,
report_duplicate_details = TRUE,
detect_near_duplicates = TRUE,
auto_convert_dates = FALSE,
feature_engineering = FALSE,
outlier_method = c("iqr", "zscore", "dbscan", "lof"),
run_distribution_checks = TRUE,
normality_tests = c("shapiro"),
pairwise_matrix = TRUE,
max_scatter_cols = 5,
grouped_plots = TRUE,
use_upset_missing = TRUE
)
Arguments
data |
A |
label |
A character string specifying the name of the target or label column (optional). If provided, certain grouped plots and class imbalance checks will be performed. |
visualize |
A character vector specifying which visualizations to produce.
Possible values: |
save_results |
Logical. If |
output_dir |
A character string specifying the output directory for saving results
(if |
sample_size |
An integer specifying a random sample size for the data to be used in
visualizations. If |
interactive |
Logical. If |
corr_threshold |
Numeric. Threshold above which correlations (in absolute value)
are flagged as high. Defaults to |
auto_convert_numeric |
Logical. If |
visualize_missing |
Logical. If |
imputation_suggestions |
Logical. If |
report_duplicate_details |
Logical. If |
detect_near_duplicates |
Logical. Placeholder for near-duplicate (fuzzy) detection. Currently not implemented. |
auto_convert_dates |
Logical. If |
feature_engineering |
Logical. If |
outlier_method |
A character string indicating which outlier detection method(s) to apply.
One of |
run_distribution_checks |
Logical. If |
normality_tests |
A character vector specifying which normality tests to run.
Possible values include |
pairwise_matrix |
Logical. If |
max_scatter_cols |
Integer. Maximum number of numeric columns to include in the pairwise matrix. |
grouped_plots |
Logical. If |
use_upset_missing |
Logical. If |
Details
This function automates many steps of EDA:
Automatically detects numeric vs. categorical variables.
Auto-converts columns that look numeric (and optionally date-like).
Summarizes data structure, missingness, duplication, and potential ID columns.
Computes correlation matrix and flags highly correlated pairs.
(Optional) Outlier detection using IQR, Z-score, DBSCAN, or LOF methods.
(Optional) Normality tests on numeric columns.
Saves all results and an R Markdown report if
save_results = TRUE
.
Value
A (silent) list containing:
-
data_overview
- A basic overview (head, unique values, skim summary). -
summary_stats
- Summary statistics for numeric columns. -
freq_tables
- Frequency tables for factor columns. -
missing_data
- Missing data overview (count, percentage). -
duplicated_rows
- Count of duplicated rows. -
class_imbalance
- Class distribution iflabel
is provided and is categorical. -
correlation_matrix
- The correlation matrix for numeric variables. -
zero_variance_cols
- Columns with near-zero variance. -
potential_id_cols
- Columns with unique values in every row. -
date_time_cols
- Columns recognized as date/time. -
high_corr_pairs
- Pairs of variables with correlation abovecorr_threshold
. -
outlier_method
- The chosen method for outlier detection. -
outlier_summary
- Outlier proportions or metrics (if computed).
If save_results = TRUE
, additional side effects include saving figures, a correlation heatmap,
and an R Markdown report in the specified directory.
Fast Machine Learning Function
Description
Trains and evaluates multiple classification or regression models automatically detecting the task based on the target variable type.
Usage
fastml(
data = NULL,
train_data = NULL,
test_data = NULL,
label,
algorithms = "all",
task = "auto",
test_size = 0.2,
resampling_method = "cv",
folds = ifelse(grepl("cv", resampling_method), 10, 25),
repeats = ifelse(resampling_method == "repeatedcv", 1, NA),
event_class = "first",
exclude = NULL,
recipe = NULL,
tune_params = NULL,
metric = NULL,
algorithm_engines = NULL,
n_cores = 1,
stratify = TRUE,
impute_method = "error",
impute_custom_function = NULL,
encode_categoricals = TRUE,
scaling_methods = c("center", "scale"),
summaryFunction = NULL,
use_default_tuning = FALSE,
tuning_strategy = "grid",
tuning_iterations = 10,
early_stopping = FALSE,
adaptive = FALSE,
learning_curve = FALSE,
seed = 123
)
Arguments
data |
A data frame containing the complete dataset. If both 'train_data' and 'test_data' are 'NULL', 'fastml()' will split this into training and testing sets according to 'test_size' and 'stratify'. Defaults to 'NULL'. |
train_data |
A data frame pre-split for model training. If provided, 'test_data' must also be supplied, and no internal splitting will occur. Defaults to 'NULL'. |
test_data |
A data frame pre-split for model evaluation. If provided, 'train_data' must also be supplied, and no internal splitting will occur. Defaults to 'NULL'. |
label |
A string specifying the name of the target variable. |
algorithms |
A vector of algorithm names to use. Default is |
task |
Character string specifying model type selection. Use "auto" to let the function detect whether the target is for classification or regression based on the data, or explicitly set to "classification" or "regression". |
test_size |
A numeric value between 0 and 1 indicating the proportion of the data to use for testing. Default is |
resampling_method |
A string specifying the resampling method for model evaluation. Default is |
folds |
An integer specifying the number of folds for cross-validation. Default is |
repeats |
Number of times to repeat cross-validation (only applicable for methods like "repeatedcv"). |
event_class |
A single string. Either "first" or "second" to specify which level of truth to consider as the "event". Default is "first". |
exclude |
A character vector specifying the names of the columns to be excluded from the training process. |
recipe |
A user-defined |
tune_params |
A list specifying hyperparameter tuning ranges. Default is |
metric |
The performance metric to optimize during training. |
algorithm_engines |
A named list specifying the engine to use for each algorithm. |
n_cores |
An integer specifying the number of CPU cores to use for parallel processing. Default is |
stratify |
Logical indicating whether to use stratified sampling when splitting the data. Default is |
impute_method |
Method for handling missing values. Options include:
Default is |
impute_custom_function |
A function that takes a data.frame as input and returns an imputed data.frame. Used only if |
encode_categoricals |
Logical indicating whether to encode categorical variables. Default is |
scaling_methods |
Vector of scaling methods to apply. Default is |
summaryFunction |
A custom summary function for model evaluation. Default is |
use_default_tuning |
Logical indicating whether to use default tuning grids when |
tuning_strategy |
A string specifying the tuning strategy. Options might include |
tuning_iterations |
Number of tuning iterations (applicable for Bayesian or other iterative search methods). Default is |
early_stopping |
Logical indicating whether to use early stopping in Bayesian tuning methods (if supported). Default is |
adaptive |
Logical indicating whether to use adaptive/racing methods for tuning. Default is |
learning_curve |
Logical. If TRUE, generate learning curves (performance vs. training size). |
seed |
An integer value specifying the random seed for reproducibility. |
Details
Fast Machine Learning Function
Trains and evaluates multiple classification or regression models. The function automatically detects the task based on the target variable type and can perform advanced hyperparameter tuning using various tuning strategies.
Value
An object of class fastml
containing the best model, performance metrics, and other information.
Examples
# Example 1: Using the iris dataset for binary classification (excluding 'setosa')
data(iris)
iris <- iris[iris$Species != "setosa", ] # Binary classification
iris$Species <- factor(iris$Species)
# Train models
model <- fastml(
data = iris,
label = "Species",
algorithms = c("rand_forest", "xgboost", "svm_rbf"), algorithm_engines = c(
list(rand_forest = c("ranger","aorsf", "partykit", "randomForest")))
)
# View model summary
summary(model)
Flatten and Rename Models
Description
Flattens a nested list of models and renames the elements by combining the outer and inner list names.
Usage
flatten_and_rename_models(models)
Arguments
models |
A nested list of models. The outer list should have names. If an inner element is a named list, the names will be combined with the outer name in the format |
Details
The function iterates over each element of the outer list. For each element, if it is a list with names, the function concatenates the outer list name and the inner names using paste0
and setNames
. If an element is not a list or does not have names, it is included in the result without modification.
Value
A flattened list with each element renamed according to its original outer and inner list names.
Framingham Heart Study Data
Description
This dataset is derived from the Framingham Heart Study and contains various clinical and demographic variables used to predict coronary heart disease risk over a ten-year period.
Format
- male
Integer indicator for male sex.
- age
Participant age in years.
- education
Education level.
- currentSmoker
Whether the participant currently smokes.
- cigsPerDay
Number of cigarettes smoked per day.
- BPMeds
Whether blood pressure medication is used.
- prevalentStroke
History of stroke at baseline.
- prevalentHyp
History of hypertension at baseline.
- diabetes
Diabetes diagnosis.
- totChol
Total cholesterol.
- sysBP
Systolic blood pressure.
- diaBP
Diastolic blood pressure.
- BMI
Body mass index.
- heartRate
Heart rate.
- glucose
Glucose level.
- TenYearCHD
Ten year risk of coronary heart disease.
Get Best Model Indices by Metric and Group
Description
Identifies and returns the indices of rows in a data frame where the specified metric reaches the overall maximum within groups defined by one or more columns.
Usage
get_best_model_idx(df, metric, group_cols = c("Model", "Engine"))
Arguments
df |
A data frame containing model performance metrics and grouping columns. |
metric |
A character string specifying the name of the metric column in |
group_cols |
A character vector of column names used for grouping. Defaults to |
Details
The function converts the metric values to numeric and creates a combined grouping factor using the specified group_cols
. It then computes the maximum metric value within each group and determines the overall best metric value across the entire data frame. Finally, it returns the indices of rows belonging to groups that achieve this overall maximum.
Value
A numeric vector of row indices in df
corresponding to groups whose maximum metric equals the overall best metric value.
Get Best Model Names
Description
Extracts and returns the best engine names from a named list of model workflows.
Usage
get_best_model_names(models)
Arguments
models |
A named list where each element corresponds to an algorithm and contains a list of model workflows.
Each workflow should be compatible with |
Details
For each algorithm, the function extracts the engine names from the model workflows using tune::extract_fit_parsnip
.
It then chooses "randomForest"
if it is available; otherwise, it selects the first non-NA
engine.
If no engine names can be extracted for an algorithm, NA_character_
is returned.
Value
A named character vector. The names of the vector correspond to the algorithm names, and the values represent the chosen best engine name for that algorithm.
Get Best Workflows
Description
Extracts the best workflows from a nested list of model workflows based on the provided best model names.
Usage
get_best_workflows(models, best_model_name)
Arguments
models |
A nested list of model workflows. Each element should correspond to an algorithm and contain sublists keyed by engine names. |
best_model_name |
A named character vector where the names represent algorithm names and the values represent the chosen best engine for each algorithm. |
Details
The function iterates over each element in best_model_name
and attempts to extract the corresponding workflow from models
using the specified engine. If the workflow for an algorithm-engine pair is not found, a warning is issued and NULL
is returned for that entry.
Value
A named list of workflows corresponding to the best engine for each algorithm. Each list element is named in the format "algorithm (engine)"
.
Get Default Engine
Description
Returns the default engine corresponding to the specified algorithm.
Usage
get_default_engine(algo)
Arguments
algo |
A character string specifying the name of the algorithm. The value should match one of the supported algorithm names. |
Details
The function uses a switch
statement to select the default engine based on the given algorithm. If the provided algorithm does not have a defined default engine, the function terminates with an error.
Value
A character string containing the default engine name associated with the provided algorithm.
Get Default Parameters for an Algorithm
Description
Returns a list of default tuning parameters for the specified algorithm based on the task type, number of predictors, and engine.
Usage
get_default_params(algo, task, num_predictors = NULL, engine = NULL)
Arguments
algo |
A character string specifying the algorithm name. Supported values include:
|
task |
A character string specifying the task type, typically |
num_predictors |
An optional numeric value indicating the number of predictors. This value is used to compute default values for parameters such as |
engine |
An optional character string specifying the engine to use. If not provided, a default engine is chosen where applicable. |
Details
The function employs a switch
statement to select and return a list of default parameters tailored for the given algorithm, task, and engine. The defaults vary by algorithm and, in some cases, by engine. For example:
For
"rand_forest"
, ifengine
is not provided, it defaults to"ranger"
. The parameters such asmtry
,trees
, andmin_n
are computed based on the task and the number of predictors.For
"C5_rules"
, the defaults includetrees
,min_n
, andsample_size
.For
"xgboost"
and"lightgbm"
, default values are provided for parameters like tree depth, learning rate, and sample size.For
"logistic_reg"
and"multinom_reg"
, the function returns defaults for regularization parameters (penalty
andmixture
) that vary with the specified engine.For
"decision_tree"
, the parameters (such astree_depth
,min_n
, andcost_complexity
) are set based on the engine (e.g.,"rpart"
,"C5.0"
,"partykit"
,"spark"
).Other algorithms, including
"svm_linear"
,"svm_rbf"
,"nearest_neighbor"
,"naive_Bayes"
,"mlp"
,"deep_learning"
,"elastic_net"
,"bayes_glm"
,"pls"
,"linear_reg"
,"ridge_regression"
, and"lasso_regression"
, have their respective default parameter lists.
Value
A list of default parameter settings for the specified algorithm. If the algorithm is not recognized, the function returns NULL
.
Get Default Tuning Parameters
Description
Returns a list of default tuning parameter ranges for a specified algorithm based on the provided training data, outcome label, and engine.
Usage
get_default_tune_params(algo, train_data, label, engine)
Arguments
algo |
A character string specifying the algorithm name. Supported values include: |
train_data |
A data frame containing the training data. |
label |
A character string specifying the name of the outcome variable in |
engine |
A character string specifying the engine to be used for the algorithm. Different engines may have different tuning parameter ranges. |
Details
The function first determines the number of predictors by removing the outcome variable (specified by label
) from train_data
. It then uses a switch
statement to select a list of default tuning parameter ranges tailored for the specified algorithm and engine. The tuning ranges have been adjusted for efficiency and may include parameters such as mtry
, trees
, min_n
, and others depending on the algorithm.
Value
A list of tuning parameter ranges for the specified algorithm. If no tuning parameters are defined for the given algorithm, the function returns NULL
.
Get Engine Names from Model Workflows
Description
Extracts and returns a list of unique engine names from a list of model workflows.
Usage
get_engine_names(models)
Arguments
models |
A list where each element is a list of model workflows. Each workflow is expected to contain a fitted model that can be processed with |
Details
The function applies tune::extract_fit_parsnip
to each model workflow to extract the fitted model object. It then retrieves the engine name from the model specification (spec$engine
). If the extraction fails, NA_character_
is returned for that workflow. Finally, the function removes any duplicate engine names using unique
.
Value
A list of character vectors. Each vector contains the unique engine names extracted from the corresponding element of models
.
Get Model Engine Names
Description
Extracts and returns a named vector mapping algorithm names to engine names from a nested list of model workflows.
Usage
get_model_engine_names(models)
Arguments
models |
A nested list of model workflows. Each inner list should contain model objects from which a fitted model can be extracted using |
Details
The function iterates over a nested list of model workflows and, for each workflow, attempts to extract the fitted model object using tune::extract_fit_parsnip
. If successful, it retrieves the algorithm name from the first element of the class attribute of the model specification and the engine name from the specification. The results are combined into a named vector.
Value
A named character vector where the names correspond to algorithm names (e.g., "rand_forest"
, "logistic_reg"
) and the values correspond to the associated engine names (e.g., "ranger"
, "glm"
).
Load Model Function
Description
Loads a trained model object from a file.
Usage
load_model(filepath)
Arguments
filepath |
A string specifying the file path to load the model from. |
Value
An object of class fastml
.
Plot Methods for fastml
Objects
Description
plot.fastml
produces visual diagnostics for a trained fastml
object.
Usage
## S3 method for class 'fastml'
plot(
x,
algorithm = "best",
type = c("all", "bar", "roc", "confusion", "calibration", "residual"),
...
)
Arguments
x |
A |
algorithm |
Character vector specifying which algorithm(s) to include when
generating certain plots (e.g., ROC curves). Defaults to |
type |
Character vector indicating which plot(s) to produce. Options are:
|
... |
Additional arguments (currently unused). |
Details
When type = "all"
, plot.fastml
will produce a bar plot of metrics,
ROC curves (classification), confusion matrix, calibration plot, and residual
diagnostics (regression). If you specify a subset of types, only those will be drawn.
Examples
## Create a binary classification dataset from iris
data(iris)
iris <- iris[iris$Species != "setosa",]
iris$Species <- factor(iris$Species)
## Fit fastml model on binary classification task
model <- fastml(data = iris, label = "Species", algorithms = c("rand_forest", "svm_rbf"))
## 1. Plot all available diagnostics
plot(model, type = "all")
## 2. Bar plot of performance metrics
plot(model, type = "bar")
## 3. ROC curves (only for classification models)
plot(model, type = "roc")
## 4. Calibration plot (requires 'probably' package)
plot(model, type = "calibration")
## 5. ROC curves for specific algorithm(s) only
plot(model, type = "roc", algorithm = "rand_forest")
## 6. Residual diagnostics (only available for regression tasks)
model <- fastml(data = mtcars, label = "mpg", algorithms = c("linear_reg", "xgboost"))
plot(model, type = "residual")
Predict method for fastml objects
Description
Generates predictions from a trained 'fastml' object on new data. Supports both single-model and multi-model workflows, and handles classification and regression tasks with optional post-processing and verbosity.
Usage
## S3 method for class 'fastml'
predict(
object,
newdata,
type = "auto",
model_name = NULL,
verbose = FALSE,
postprocess_fn = NULL,
...
)
Arguments
object |
A fitted 'fastml' object created by the 'fastml()' function. |
newdata |
A data frame or tibble containing new predictor data for which to generate predictions. |
type |
Type of prediction to return. One of '"auto"' (default), '"class"', '"prob"', or '"numeric"'. - '"auto"': chooses '"class"' for classification and '"numeric"' for regression. - '"prob"': returns class probabilities (only for classification). - '"class"': returns predicted class labels. - '"numeric"': returns predicted numeric values (for regression). |
model_name |
(Optional) Name of a specific model to use when 'object$best_model' contains multiple models. |
verbose |
Logical; if 'TRUE', prints progress messages showing which models are used during prediction. |
postprocess_fn |
(Optional) A function to apply to the final predictions (e.g., inverse transforms, thresholding). |
... |
Additional arguments (currently unused). |
Value
A vector of predictions, or a named list of predictions (if multiple models are used). If 'postprocess_fn' is supplied, its output will be returned instead.
Examples
## Not run:
set.seed(123)
model <- fastml(iris, label = "Species")
test_data <- iris[sample(1:150, 20),-5]
## Best model(s) predictions
preds <- predict(model, newdata = test_data)
## Predicted class probabilities using best model(s)
probs <- predict(model, newdata = test_data, type = "prob")
## Prediction from a specific model by name
single_model_preds <- predict(model, newdata = test_data, model_name = "rand_forest (ranger)")
## End(Not run)
Process Model and Compute Performance Metrics
Description
Finalizes a tuning result or utilizes an already fitted workflow to generate predictions on test data and compute performance metrics.
Usage
process_model(
model_obj,
model_id,
task,
test_data,
label,
event_class,
engine,
train_data,
metric
)
Arguments
model_obj |
A model object, which can be either a tuning result (an object inheriting from |
model_id |
A unique identifier for the model, used in warning messages if issues arise during processing. |
task |
A character string indicating the type of task, either |
test_data |
A data frame containing the test data on which predictions will be generated. |
label |
A character string specifying the name of the outcome variable in |
event_class |
For classification tasks, a character string specifying which event class to consider as positive (accepted values: |
engine |
A character string specifying the modeling engine used. This parameter affects prediction types and metric computations. |
train_data |
A data frame containing the training data used to fit tuned models. |
metric |
A character string specifying the metric name used to select the best tuning parameters. |
Details
The function first checks if model_obj
is a tuning result. If so, it attempts to:
Select the best tuning parameters using
tune::select_best
(note that the metric used for selection should be defined in the calling environment).Extract the model specification and preprocessor from
model_obj
usingworkflows::pull_workflow_spec
andworkflows::pull_workflow_preprocessor
, respectively.Finalize the model specification with the selected parameters via
tune::finalize_model
.Rebuild the workflow using
workflows::workflow
,workflows::add_recipe
, andworkflows::add_model
, and fit the finalized workflow withparsnip::fit
on the suppliedtrain_data
.
If model_obj
is already a fitted workflow, it is used directly.
For classification tasks, the function makes class predictions (and probability predictions if engine
is not "LiblineaR"
) and computes performance metrics using functions from the yardstick
package. In binary classification, the positive class is determined based on the event_class
argument and ROC AUC is computed accordingly. For multiclass classification, macro-averaged metrics and ROC AUC (using weighted estimates) are calculated.
For regression tasks, the function predicts outcomes and computes regression metrics (RMSE, R-squared, and MAE).
If the number of predictions does not match the number of rows in test_data
, the function stops with an informative error message regarding missing values and imputation options.
Value
A list with two components:
- performance
A data frame of performance metrics. For classification tasks, metrics include accuracy, kappa, sensitivity, specificity, precision, F-measure, and ROC AUC (when applicable). For regression tasks, metrics include RMSE, R-squared, and MAE.
- predictions
A data frame containing the test data augmented with predicted classes and, when applicable, predicted probabilities.
Clean Column Names or Character Vectors by Removing Special Characters
Description
This function can operate on either a data frame or a character vector:
-
Data frame: Detects columns whose names contain any character that is not a letter, number, or underscore, removes colons, replaces slashes with underscores, and spaces with underscores.
-
Character vector: Applies the same cleaning rules to every element of the vector.
Usage
sanitize(x)
Arguments
x |
A data frame or character vector to be cleaned. |
Value
If
x
is a data frame: returns a data frame with cleaned column names.If
x
is a character vector: returns a character vector with cleaned elements.
Save Model Function
Description
Saves the trained model object to a file.
Usage
save.fastml(model, filepath)
Arguments
model |
An object of class |
filepath |
A string specifying the file path to save the model. |
Value
No return value, called for its side effect of saving the model object to a file.
Summary Function for fastml (Using yardstick for ROC Curves)
Description
Summarizes the results of machine learning models trained using the 'fastml' package. Depending on the task type (classification or regression), it provides customized output such as performance metrics, best hyperparameter settings, and confusion matrices. It is designed to be informative and readable, helping users quickly interpret model results.
Usage
## S3 method for class 'fastml'
summary(
object,
algorithm = "best",
type = c("all", "metrics", "params", "conf_mat"),
sort_metric = NULL,
...
)
Arguments
object |
An object of class |
algorithm |
A vector of algorithm names to display summary. Default is |
type |
Character vector indicating which outputs to produce.
Options are |
sort_metric |
The metric to sort by. Default uses optimized metric. |
... |
Additional arguments. |
Details
For classification tasks, the summary includes metrics such as Accuracy, F1 Score, Kappa, Precision, ROC AUC, Sensitivity, and Specificity. A confusion matrix is also provided for the best model(s). For regression tasks, the summary reports RMSE, R-squared, and MAE.
Users can control the type of output with the 'type' argument: 'metrics' displays model performance metrics. 'params' shows the best hyperparameter settings. 'conf_mat' prints confusion matrices (only for classification). 'all' includes all of the above.
If multiple algorithms are trained, the summary highlights the best model based on the optimized metric.
Value
Prints summary of fastml models.
Train Specified Machine Learning Algorithms on the Training Data
Description
Trains specified machine learning algorithms on the preprocessed training data.
Usage
train_models(
train_data,
label,
task,
algorithms,
resampling_method,
folds,
repeats,
tune_params,
metric,
summaryFunction = NULL,
seed = 123,
recipe,
use_default_tuning = FALSE,
tuning_strategy = "grid",
tuning_iterations = 10,
early_stopping = FALSE,
adaptive = FALSE,
algorithm_engines = NULL
)
Arguments
train_data |
Preprocessed training data frame. |
label |
Name of the target variable. |
task |
Type of task: "classification" or "regression". |
algorithms |
Vector of algorithm names to train. |
resampling_method |
Resampling method for cross-validation (e.g., "cv", "repeatedcv", "boot", "none"). |
folds |
Number of folds for cross-validation. |
repeats |
Number of times to repeat cross-validation (only applicable for methods like "repeatedcv"). |
tune_params |
List of hyperparameter tuning ranges. |
metric |
The performance metric to optimize. |
summaryFunction |
A custom summary function for model evaluation. Default is |
seed |
An integer value specifying the random seed for reproducibility. |
recipe |
A recipe object for preprocessing. |
use_default_tuning |
Logical indicating whether to use default tuning grids when |
tuning_strategy |
A string specifying the tuning strategy ("grid", "bayes", or "none"), possibly with adaptive methods. |
tuning_iterations |
Number of iterations for iterative tuning methods. |
early_stopping |
Logical for early stopping in Bayesian tuning. |
adaptive |
Logical indicating whether to use adaptive/racing methods. |
algorithm_engines |
A named list specifying the engine to use for each algorithm. |
Value
A list of trained model objects.