Introduction to sensAI: Supervised Learning with VectorModels#

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%load_ext autoreload
%autoreload 2
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import sys
sys.path.append("../src")

import sensai
import numpy as np

Logging#

sensAI will log relevant activies and inform about ongoing processes as well as results via the log. It is therefore highly recommended that logging be enabled when using sensAI.

sensAI provides a logging module which includes Python’s standard logging module and adds some additional functionality. To enable logging, simply use its configureLogging function.

from sensai.util import logging

logging.configure(level=logging.INFO)

To additionally write log output to a file, use the function logging.add_file_logger.

VectorModels#

The central base class for supervised learning problems in sensAI is VectorModel. A VectorModel is any model which operates on data points that can be reprsented as vectors of data. Here, vector is to be understood not in the mathematical sense but in the computer science sense, where a vector is simply an array of (potentially arbitaririly complex) data. (The mathematical equivalent is a tuple.) Models are typically expected to be able to process more than one data point at a time and thus should be able to process a sequence of vectors.

We use pandas DataFrames to represent such sequences of data points. Note that pandas DataFrames are not limited to primitive data types but can hold arbitrary objects in every cell. When dealing with a large number of inputs, DataFrames also provide at least limited meta-information in the form of column names, so we do not lose track of what is contained in which element of a data point (vector).

VectorModel itself is an abstract base class, which provides a lot of useful functionality that all its specialisations inherit (as we will see later, particularly in the more advanced tutorials). The class is specialised in VectorClassificationModel and VectorRegressionModel, which in turn are specialised for various machine learning frameworks (such as sklearn and PyTorch) or can be directly subclassed to create your own model.

In this tutorial, we will be dealing with a classification problem. Therefore, we will apply subclasses of VectorClassificationModel such as SkLearnRandomForestVectorClassificationModel. As an sklearn classification model which uses a well-defined training and inference interface, the implementation of the class is essentially justa few lines of code (given the intermediate abstraction AbstractSkLearnVectorClassificationModel for all classification models that use the sklearn protocol).

Training and Evaluating Models#

First, let us load a dataset which we can experiment. sklearn provides, for example, the Iris classification dataset, where the task is to differentiate three different types of flowers based on measurements of their petals and sepals.

import sklearn.datasets
import pandas as pd

iris_data = sklearn.datasets.load_iris()
iris_input_df = pd.DataFrame(iris_data["data"], columns=iris_data["feature_names"]).reset_index(drop=True)
iris_output_df = pd.DataFrame({"class": [iris_data["target_names"][idx] for idx in iris_data["target"]]}).reset_index(drop=True)

Here’s a sample of the data, combining both the inputs and outputs:

iris_combined_df = pd.concat((iris_input_df, iris_output_df), axis=1)
iris_combined_df.sample(10)
sepal length (cm) sepal width (cm) petal length (cm) petal width (cm) class
27 5.2 3.5 1.5 0.2 setosa
98 5.1 2.5 3.0 1.1 versicolor
19 5.1 3.8 1.5 0.3 setosa
122 7.7 2.8 6.7 2.0 virginica
23 5.1 3.3 1.7 0.5 setosa
10 5.4 3.7 1.5 0.2 setosa
103 6.3 2.9 5.6 1.8 virginica
148 6.2 3.4 5.4 2.3 virginica
80 5.5 2.4 3.8 1.1 versicolor
82 5.8 2.7 3.9 1.2 versicolor

When working with sensAI, we typically use DataFrames such as this as the starting point.

We create an instance of InputOutputData from the two data frames.

iris_io_data = sensai.InputOutputData(iris_input_df, iris_output_df)

Low-Level Training and Inference#

We use a DataSplitter (see subclasses) to split the data into a training and test set, specifically a DataSplitterFractional.

data_splitter = sensai.data.DataSplitterFractional(0.8, shuffle=True)
training_io_data, test_io_data = data_splitter.split(iris_io_data)

Now we are ready to train a model. Let us train a random forest classifier, which should work well for this sort of problem. sensAI provides models from various libraries, including scikit-learn, PyTorch, lightgbm, xgboost, catboost, and TensorFlow.

In this case, let us use the random forest implementation from sklearn, which is provided via the wrapper class SkLearnRandomForestVectorClassificationModel.

sensAI’s VectorModel classes (specialised for classification and regression) provide a common interface with a lot of useful functionality, which we will see later.

random_forest_model = sensai.sklearn.classification.SkLearnRandomForestVectorClassificationModel(
    min_samples_leaf=2).with_name("RandomForest")

The class suppports all the parameters supported by the original sklearn model. In this case, we only set the minimum number of samples that must end up in each leaf.

We train the model using the fit_input_output_data method; we could also use the fit method, which is analogous to the sklearn interface and takes two arguments (input, output).

random_forest_model.fit_input_output_data(training_io_data)
random_forest_model
INFO  2026-02-24 20:07:37,689 sensai.vector_model:fit:359 - Fitting SkLearnRandomForestVectorClassificationModel instance
INFO  2026-02-24 20:07:37,691 sensai.sklearn.sklearn_base:_fit_classifier:314 - Fitting sklearn classifier of type RandomForestClassifier
INFO  2026-02-24 20:07:37,795 sensai.vector_model:fit:388 - Fitting completed in 0.10 seconds: SkLearnRandomForestVectorClassificationModel[featureGenerator=None, rawInputTransformerChain=DataFrameTransformerChain[dataFrameTransformers=[]], featureTransformerChain=DataFrameTransformerChain[dataFrameTransformers=[]], fitArgs={}, useBalancedClassWeights=False, useLabelEncoding=False, name='RandomForest', model='RandomForestClassifier(min_samples_leaf=2, random_state=42)']
SkLearnRandomForestVectorClassificationModel[id=139641071791760, featureGenerator=None, rawInputTransformerChain=DataFrameTransformerChain[dataFrameTransformers=[]], featureTransformerChain=DataFrameTransformerChain[dataFrameTransformers=[]], fitArgs={}, useBalancedClassWeights=False, useLabelEncoding=False, name='RandomForest', model='RandomForestClassifier(min_samples_leaf=2, random_state=42)']

We can now apply the trained model and predict the outputs for the test set we reserved.

predicted_outputs_df = random_forest_model.predict(test_io_data.inputs)
predicted_outputs_df.head(5)
class
91 versicolor
41 setosa
58 versicolor
90 versicolor
48 setosa

Let’s compare some of the predictions to the ground truth.

pd.concat((predicted_outputs_df.rename(columns={"class": "predictedClass"}), test_io_data.outputs), axis=1).sample(10)
predictedClass class
106 versicolor virginica
21 setosa setosa
116 virginica virginica
130 virginica virginica
58 versicolor versicolor
129 virginica virginica
103 virginica virginica
144 virginica virginica
88 versicolor versicolor
107 virginica virginica

Using the ground truth and predicted values, we could now compute the metrics we’re interested in. We could, for example, use the metrics implemented in sklearn to analyse the result. Yet sensAI already provides abstractions that facilitate the generation of metrics and the collection of results. Read on!

Using Evaluators#

sensAI provides evaluator abstractions which facilitate the training and evaluation of models.

For a classification problem, we instantiate a VectorClassificationModelEvaluator. An evaluator serves to evaluate one or more models based on the same data, so we construct it with the data and instructions on how to handle/split the data for evaluation.

evaluator_params = sensai.evaluation.ClassificationEvaluatorParams(data_splitter=data_splitter, compute_probabilities=True)
evaluator = sensai.evaluation.VectorClassificationModelEvaluator(iris_io_data, params=evaluator_params)

We can use this evaluator to evaluate one or more models. Let us evaluate the random forest model from above.

evaluator.fit_model(random_forest_model)
eval_data = evaluator.eval_model(random_forest_model)
INFO  2026-02-24 20:07:37,898 sensai.vector_model:fit:359 - Fitting SkLearnRandomForestVectorClassificationModel instance
INFO  2026-02-24 20:07:37,900 sensai.sklearn.sklearn_base:_fit_classifier:314 - Fitting sklearn classifier of type RandomForestClassifier
INFO  2026-02-24 20:07:38,003 sensai.vector_model:fit:388 - Fitting completed in 0.10 seconds: SkLearnRandomForestVectorClassificationModel[featureGenerator=None, rawInputTransformerChain=DataFrameTransformerChain[dataFrameTransformers=[]], featureTransformerChain=DataFrameTransformerChain[dataFrameTransformers=[]], fitArgs={}, useBalancedClassWeights=False, useLabelEncoding=False, name='RandomForest', model='RandomForestClassifier(min_samples_leaf=2, random_state=42)']

The evaluation data holds, in particular, an EvalStats object, which can provide data on the quality of the results. Depending on the type of problem, many metrics will already be computed by default.

eval_stats = eval_data.get_eval_stats()
eval_stats
ClassificationEvalStats[id=139639878166480, accuracy=0.9666666666666667, balancedAccuracy=0.9722222222222222, geoMeanTrueClassProb=0.8890980234758366, N=30]

We can get the metrics in a dictionary as follows:

eval_stats.metrics_dict()
{'accuracy': 0.9666666666666667,
 'balancedAccuracy': 0.9722222222222222,
 'geoMeanTrueClassProb': np.float64(0.8890980234758366)}

We can compute additional metrics by passing a metric to the compute_metric_value method, but we could also have added additional metrics to the evaluator_params above and have the metric included in all results.

Let’s see how frequently the true class is among the top two most probable classes.

eval_stats.compute_metric_value(sensai.eval_stats_classification.ClassificationMetricTopNAccuracy(2))
1.0

The EvalStats object can also be used to generate plots, such as a confusion matrix or a precision-recall plot for binary classification.

eval_stats.plot_confusion_matrix(normalize=True);
../_images/cd9dd762dd1e477e4cd56870a8526da1d95a59ad53a838e0c11ebee48dec1d49.png

Using the Fully-Integrated Evaluation Utilities#

sensAI’s evaluation utilities take things one step further and assist you in out all the evaluation steps and results computations in a single call.

You can perform evaluations based on a single split or cross-validation. We simply declare the necessary parameters for both types of computations (or the one type we seek to carry out).

evaluatorParams = sensai.evaluation.ClassificationEvaluatorParams(
    data_splitter=data_splitter, compute_probabilities=True,
    additional_metrics=[sensai.eval_stats_classification.ClassificationMetricTopNAccuracy(2)])
cross_validator_params = sensai.evaluation.crossval.VectorModelCrossValidatorParams(folds=10,
    evaluator_params=evaluator_params)
eval_util = sensai.evaluation.ClassificationModelEvaluation(iris_io_data,
    evaluator_params=evaluatorParams, cross_validator_params=cross_validator_params)

In practice, we will usually want to save evaluation results. The evaluation methods of eval_util take a parameter result_writer which allows us to define where results shall be written. Within this notebook, we shall simply inspect the resulting metrics in the log that is printed, and we shall configure plots to be shown directly.

Simple Evaluation#

We can perform the same evaluation as above (which uses a single split) like so:

eval_util.perform_simple_evaluation(random_forest_model, show_plots=True)
INFO  2026-02-24 20:07:38,365 sensai.evaluation.eval_util:perform_simple_evaluation:288 - Evaluating SkLearnRandomForestVectorClassificationModel[featureGenerator=None, rawInputTransformerChain=DataFrameTransformerChain[dataFrameTransformers=[]], featureTransformerChain=DataFrameTransformerChain[dataFrameTransformers=[]], fitArgs={}, useBalancedClassWeights=False, useLabelEncoding=False, name='RandomForest', model='RandomForestClassifier(min_samples_leaf=2, random_state=42)'] via <sensai.evaluation.evaluator.VectorClassificationModelEvaluator object at 0x7f0071177c70>
INFO  2026-02-24 20:07:38,365 sensai.vector_model:fit:359 - Fitting SkLearnRandomForestVectorClassificationModel instance
INFO  2026-02-24 20:07:38,366 sensai.sklearn.sklearn_base:_fit_classifier:314 - Fitting sklearn classifier of type RandomForestClassifier
INFO  2026-02-24 20:07:38,469 sensai.vector_model:fit:388 - Fitting completed in 0.10 seconds: SkLearnRandomForestVectorClassificationModel[featureGenerator=None, rawInputTransformerChain=DataFrameTransformerChain[dataFrameTransformers=[]], featureTransformerChain=DataFrameTransformerChain[dataFrameTransformers=[]], fitArgs={}, useBalancedClassWeights=False, useLabelEncoding=False, name='RandomForest', model='RandomForestClassifier(min_samples_leaf=2, random_state=42)']
INFO  2026-02-24 20:07:38,482 sensai.evaluation.eval_util:gather_results:296 - Evaluation results for class: ClassificationEvalStats[accuracy=0.9666666666666667, balancedAccuracy=0.9722222222222222, geoMeanTrueClassProb=0.8890980234758366, top2Accuracy=1.0, N=30]
<sensai.evaluation.evaluator.VectorClassificationModelEvaluationData at 0x7f0070d25e70>
../_images/da7fe7d18b10c557cc582b3a42f955b657b3e9f1d7e28c788e78a18607283a7a.png ../_images/b2906d58806c19a551c4edb624cd780deb6778308394b069409d51de694eb081.png

Customising the Set of Plots#

If we decide that we don’t really want to have the normalised confusion matrix, we can disable it for any further experiments.

eval_util.eval_stats_plot_collector.get_enabled_plots()
['confusion-matrix-rel',
 'confusion-matrix-abs',
 'precision-recall',
 'threshold-precision-recall',
 'threshold-counts']

Some of these are only active for binary classification. The one we don’t want is “confusion-matrix-rel”.

eval_util.eval_stats_plot_collector.disable_plots("confusion-matrix-rel")

We could also define our own plot class (by creating a new subclass of ClassificationEvalStatsPlot) and add it to the plot collector in order to have the plot auto-generated whenever we apply one of eval_util’s methods.

Cross-Validation#

We can similarly run cross-validation and produce the respective evaluation metrics with a single call.

eval_util.perform_cross_validation(random_forest_model, show_plots=True)
INFO  2026-02-24 20:07:38,959 sensai.evaluation.crossval:eval_model:192 - Training and evaluating model with fold 1/10 ...
INFO  2026-02-24 20:07:38,960 sensai.vector_model:fit:359 - Fitting SkLearnRandomForestVectorClassificationModel instance
INFO  2026-02-24 20:07:38,961 sensai.sklearn.sklearn_base:_fit_classifier:314 - Fitting sklearn classifier of type RandomForestClassifier
INFO  2026-02-24 20:07:39,139 sensai.vector_model:fit:388 - Fitting completed in 0.18 seconds: SkLearnRandomForestVectorClassificationModel[featureGenerator=None, rawInputTransformerChain=DataFrameTransformerChain[dataFrameTransformers=[]], featureTransformerChain=DataFrameTransformerChain[dataFrameTransformers=[]], fitArgs={}, useBalancedClassWeights=False, useLabelEncoding=False, name='RandomForest', model='RandomForestClassifier(min_samples_leaf=2, random_state=42)']
INFO  2026-02-24 20:07:39,151 sensai.evaluation.crossval:eval_model:201 - Evaluation result for class, fold 1/10: ClassificationEvalStats[accuracy=1.0, balancedAccuracy=1.0, geoMeanTrueClassProb=0.9553599022560102, N=15]
INFO  2026-02-24 20:07:39,151 sensai.evaluation.crossval:eval_model:192 - Training and evaluating model with fold 2/10 ...
INFO  2026-02-24 20:07:39,152 sensai.vector_model:fit:359 - Fitting SkLearnRandomForestVectorClassificationModel instance
INFO  2026-02-24 20:07:39,153 sensai.sklearn.sklearn_base:_fit_classifier:314 - Fitting sklearn classifier of type RandomForestClassifier
INFO  2026-02-24 20:07:39,256 sensai.vector_model:fit:388 - Fitting completed in 0.10 seconds: SkLearnRandomForestVectorClassificationModel[featureGenerator=None, rawInputTransformerChain=DataFrameTransformerChain[dataFrameTransformers=[]], featureTransformerChain=DataFrameTransformerChain[dataFrameTransformers=[]], fitArgs={}, useBalancedClassWeights=False, useLabelEncoding=False, name='RandomForest', model='RandomForestClassifier(min_samples_leaf=2, random_state=42)']
INFO  2026-02-24 20:07:39,267 sensai.evaluation.crossval:eval_model:201 - Evaluation result for class, fold 2/10: ClassificationEvalStats[accuracy=1.0, balancedAccuracy=1.0, geoMeanTrueClassProb=0.9734228107223192, N=15]
INFO  2026-02-24 20:07:39,268 sensai.evaluation.crossval:eval_model:192 - Training and evaluating model with fold 3/10 ...
INFO  2026-02-24 20:07:39,268 sensai.vector_model:fit:359 - Fitting SkLearnRandomForestVectorClassificationModel instance
INFO  2026-02-24 20:07:39,269 sensai.sklearn.sklearn_base:_fit_classifier:314 - Fitting sklearn classifier of type RandomForestClassifier
INFO  2026-02-24 20:07:39,373 sensai.vector_model:fit:388 - Fitting completed in 0.10 seconds: SkLearnRandomForestVectorClassificationModel[featureGenerator=None, rawInputTransformerChain=DataFrameTransformerChain[dataFrameTransformers=[]], featureTransformerChain=DataFrameTransformerChain[dataFrameTransformers=[]], fitArgs={}, useBalancedClassWeights=False, useLabelEncoding=False, name='RandomForest', model='RandomForestClassifier(min_samples_leaf=2, random_state=42)']
INFO  2026-02-24 20:07:39,385 sensai.evaluation.crossval:eval_model:201 - Evaluation result for class, fold 3/10: ClassificationEvalStats[accuracy=1.0, balancedAccuracy=1.0, geoMeanTrueClassProb=0.976458969438705, N=15]
INFO  2026-02-24 20:07:39,385 sensai.evaluation.crossval:eval_model:192 - Training and evaluating model with fold 4/10 ...
INFO  2026-02-24 20:07:39,385 sensai.vector_model:fit:359 - Fitting SkLearnRandomForestVectorClassificationModel instance
INFO  2026-02-24 20:07:39,387 sensai.sklearn.sklearn_base:_fit_classifier:314 - Fitting sklearn classifier of type RandomForestClassifier
INFO  2026-02-24 20:07:39,489 sensai.vector_model:fit:388 - Fitting completed in 0.10 seconds: SkLearnRandomForestVectorClassificationModel[featureGenerator=None, rawInputTransformerChain=DataFrameTransformerChain[dataFrameTransformers=[]], featureTransformerChain=DataFrameTransformerChain[dataFrameTransformers=[]], fitArgs={}, useBalancedClassWeights=False, useLabelEncoding=False, name='RandomForest', model='RandomForestClassifier(min_samples_leaf=2, random_state=42)']
INFO  2026-02-24 20:07:39,501 sensai.evaluation.crossval:eval_model:201 - Evaluation result for class, fold 4/10: ClassificationEvalStats[accuracy=0.9333333333333333, balancedAccuracy=0.9333333333333332, geoMeanTrueClassProb=0.9411926691126593, N=15]
INFO  2026-02-24 20:07:39,501 sensai.evaluation.crossval:eval_model:192 - Training and evaluating model with fold 5/10 ...
INFO  2026-02-24 20:07:39,502 sensai.vector_model:fit:359 - Fitting SkLearnRandomForestVectorClassificationModel instance
INFO  2026-02-24 20:07:39,503 sensai.sklearn.sklearn_base:_fit_classifier:314 - Fitting sklearn classifier of type RandomForestClassifier
INFO  2026-02-24 20:07:39,606 sensai.vector_model:fit:388 - Fitting completed in 0.10 seconds: SkLearnRandomForestVectorClassificationModel[featureGenerator=None, rawInputTransformerChain=DataFrameTransformerChain[dataFrameTransformers=[]], featureTransformerChain=DataFrameTransformerChain[dataFrameTransformers=[]], fitArgs={}, useBalancedClassWeights=False, useLabelEncoding=False, name='RandomForest', model='RandomForestClassifier(min_samples_leaf=2, random_state=42)']
INFO  2026-02-24 20:07:39,617 sensai.evaluation.crossval:eval_model:201 - Evaluation result for class, fold 5/10: ClassificationEvalStats[accuracy=1.0, balancedAccuracy=1.0, geoMeanTrueClassProb=0.9298964965102043, N=15]
INFO  2026-02-24 20:07:39,618 sensai.evaluation.crossval:eval_model:192 - Training and evaluating model with fold 6/10 ...
INFO  2026-02-24 20:07:39,618 sensai.vector_model:fit:359 - Fitting SkLearnRandomForestVectorClassificationModel instance
INFO  2026-02-24 20:07:39,619 sensai.sklearn.sklearn_base:_fit_classifier:314 - Fitting sklearn classifier of type RandomForestClassifier
INFO  2026-02-24 20:07:39,722 sensai.vector_model:fit:388 - Fitting completed in 0.10 seconds: SkLearnRandomForestVectorClassificationModel[featureGenerator=None, rawInputTransformerChain=DataFrameTransformerChain[dataFrameTransformers=[]], featureTransformerChain=DataFrameTransformerChain[dataFrameTransformers=[]], fitArgs={}, useBalancedClassWeights=False, useLabelEncoding=False, name='RandomForest', model='RandomForestClassifier(min_samples_leaf=2, random_state=42)']
INFO  2026-02-24 20:07:39,736 sensai.evaluation.crossval:eval_model:201 - Evaluation result for class, fold 6/10: ClassificationEvalStats[accuracy=0.8666666666666667, balancedAccuracy=0.8888888888888888, geoMeanTrueClassProb=0.6379522029160006, N=15]
INFO  2026-02-24 20:07:39,737 sensai.evaluation.crossval:eval_model:192 - Training and evaluating model with fold 7/10 ...
INFO  2026-02-24 20:07:39,737 sensai.vector_model:fit:359 - Fitting SkLearnRandomForestVectorClassificationModel instance
INFO  2026-02-24 20:07:39,738 sensai.sklearn.sklearn_base:_fit_classifier:314 - Fitting sklearn classifier of type RandomForestClassifier
INFO  2026-02-24 20:07:39,841 sensai.vector_model:fit:388 - Fitting completed in 0.10 seconds: SkLearnRandomForestVectorClassificationModel[featureGenerator=None, rawInputTransformerChain=DataFrameTransformerChain[dataFrameTransformers=[]], featureTransformerChain=DataFrameTransformerChain[dataFrameTransformers=[]], fitArgs={}, useBalancedClassWeights=False, useLabelEncoding=False, name='RandomForest', model='RandomForestClassifier(min_samples_leaf=2, random_state=42)']
INFO  2026-02-24 20:07:39,852 sensai.evaluation.crossval:eval_model:201 - Evaluation result for class, fold 7/10: ClassificationEvalStats[accuracy=0.8666666666666667, balancedAccuracy=0.8611111111111112, geoMeanTrueClassProb=0.8099785263057822, N=15]
INFO  2026-02-24 20:07:39,852 sensai.evaluation.crossval:eval_model:192 - Training and evaluating model with fold 8/10 ...
INFO  2026-02-24 20:07:39,854 sensai.vector_model:fit:359 - Fitting SkLearnRandomForestVectorClassificationModel instance
INFO  2026-02-24 20:07:39,855 sensai.sklearn.sklearn_base:_fit_classifier:314 - Fitting sklearn classifier of type RandomForestClassifier
INFO  2026-02-24 20:07:39,957 sensai.vector_model:fit:388 - Fitting completed in 0.10 seconds: SkLearnRandomForestVectorClassificationModel[featureGenerator=None, rawInputTransformerChain=DataFrameTransformerChain[dataFrameTransformers=[]], featureTransformerChain=DataFrameTransformerChain[dataFrameTransformers=[]], fitArgs={}, useBalancedClassWeights=False, useLabelEncoding=False, name='RandomForest', model='RandomForestClassifier(min_samples_leaf=2, random_state=42)']
INFO  2026-02-24 20:07:39,970 sensai.evaluation.crossval:eval_model:201 - Evaluation result for class, fold 8/10: ClassificationEvalStats[accuracy=1.0, balancedAccuracy=1.0, geoMeanTrueClassProb=0.9657414983648998, N=15]
INFO  2026-02-24 20:07:39,971 sensai.evaluation.crossval:eval_model:192 - Training and evaluating model with fold 9/10 ...
INFO  2026-02-24 20:07:39,972 sensai.vector_model:fit:359 - Fitting SkLearnRandomForestVectorClassificationModel instance
INFO  2026-02-24 20:07:39,973 sensai.sklearn.sklearn_base:_fit_classifier:314 - Fitting sklearn classifier of type RandomForestClassifier
INFO  2026-02-24 20:07:40,076 sensai.vector_model:fit:388 - Fitting completed in 0.10 seconds: SkLearnRandomForestVectorClassificationModel[featureGenerator=None, rawInputTransformerChain=DataFrameTransformerChain[dataFrameTransformers=[]], featureTransformerChain=DataFrameTransformerChain[dataFrameTransformers=[]], fitArgs={}, useBalancedClassWeights=False, useLabelEncoding=False, name='RandomForest', model='RandomForestClassifier(min_samples_leaf=2, random_state=42)']
INFO  2026-02-24 20:07:40,087 sensai.evaluation.crossval:eval_model:201 - Evaluation result for class, fold 9/10: ClassificationEvalStats[accuracy=1.0, balancedAccuracy=1.0, geoMeanTrueClassProb=0.9560552426688266, N=15]
INFO  2026-02-24 20:07:40,088 sensai.evaluation.crossval:eval_model:192 - Training and evaluating model with fold 10/10 ...
INFO  2026-02-24 20:07:40,088 sensai.vector_model:fit:359 - Fitting SkLearnRandomForestVectorClassificationModel instance
INFO  2026-02-24 20:07:40,090 sensai.sklearn.sklearn_base:_fit_classifier:314 - Fitting sklearn classifier of type RandomForestClassifier
INFO  2026-02-24 20:07:40,192 sensai.vector_model:fit:388 - Fitting completed in 0.10 seconds: SkLearnRandomForestVectorClassificationModel[featureGenerator=None, rawInputTransformerChain=DataFrameTransformerChain[dataFrameTransformers=[]], featureTransformerChain=DataFrameTransformerChain[dataFrameTransformers=[]], fitArgs={}, useBalancedClassWeights=False, useLabelEncoding=False, name='RandomForest', model='RandomForestClassifier(min_samples_leaf=2, random_state=42)']
INFO  2026-02-24 20:07:40,203 sensai.evaluation.crossval:eval_model:201 - Evaluation result for class, fold 10/10: ClassificationEvalStats[accuracy=0.9333333333333333, balancedAccuracy=0.9523809523809524, geoMeanTrueClassProb=0.841736920530503, N=15]
INFO  2026-02-24 20:07:40,221 sensai.evaluation.eval_util:perform_cross_validation:351 - Cross-validation results:
       mean[accuracy]  std[accuracy]  mean[balancedAccuracy]  std[balancedAccuracy]  mean[geoMeanTrueClassProb]  std[geoMeanTrueClassProb]
class            0.96       0.053333                0.963571               0.050077                     0.89878                    0.10223
<sensai.evaluation.crossval.VectorClassificationModelCrossValidationData at 0x7f007155b280>
../_images/b56ec29c5355aaff6ecb7ff75812c0e83738a25484ed5b9aa6fffbf3d7dca09e.png

As you can see, the plot we disabled earlier is no longer being generated.

Comparing Models#

A most common use case is to compare the performance of several models. The evaluation utility makes it very simple to compare any number of models.

Let’s say we want to compare the random forest we have been using thus far to a simple decision tree.

results = eval_util.compare_models([
        random_forest_model,
        sensai.sklearn.classification.SkLearnDecisionTreeVectorClassificationModel(min_samples_leaf=2).with_name("DecisionTree")],
    use_cross_validation=True)
INFO  2026-02-24 20:07:40,454 sensai.evaluation.eval_util:compare_models:400 - Evaluating model 1/2 named 'RandomForest' ...
INFO  2026-02-24 20:07:40,458 sensai.evaluation.crossval:eval_model:192 - Training and evaluating model with fold 1/10 ...
INFO  2026-02-24 20:07:40,459 sensai.vector_model:fit:359 - Fitting SkLearnRandomForestVectorClassificationModel instance
INFO  2026-02-24 20:07:40,460 sensai.sklearn.sklearn_base:_fit_classifier:314 - Fitting sklearn classifier of type RandomForestClassifier
INFO  2026-02-24 20:07:40,563 sensai.vector_model:fit:388 - Fitting completed in 0.10 seconds: SkLearnRandomForestVectorClassificationModel[featureGenerator=None, rawInputTransformerChain=DataFrameTransformerChain[dataFrameTransformers=[]], featureTransformerChain=DataFrameTransformerChain[dataFrameTransformers=[]], fitArgs={}, useBalancedClassWeights=False, useLabelEncoding=False, name='RandomForest', model='RandomForestClassifier(min_samples_leaf=2, random_state=42)']
INFO  2026-02-24 20:07:40,577 sensai.evaluation.crossval:eval_model:201 - Evaluation result for class, fold 1/10: ClassificationEvalStats[accuracy=1.0, balancedAccuracy=1.0, geoMeanTrueClassProb=0.9553599022560102, N=15]
INFO  2026-02-24 20:07:40,578 sensai.evaluation.crossval:eval_model:192 - Training and evaluating model with fold 2/10 ...
INFO  2026-02-24 20:07:40,578 sensai.vector_model:fit:359 - Fitting SkLearnRandomForestVectorClassificationModel instance
INFO  2026-02-24 20:07:40,579 sensai.sklearn.sklearn_base:_fit_classifier:314 - Fitting sklearn classifier of type RandomForestClassifier
INFO  2026-02-24 20:07:40,681 sensai.vector_model:fit:388 - Fitting completed in 0.10 seconds: SkLearnRandomForestVectorClassificationModel[featureGenerator=None, rawInputTransformerChain=DataFrameTransformerChain[dataFrameTransformers=[]], featureTransformerChain=DataFrameTransformerChain[dataFrameTransformers=[]], fitArgs={}, useBalancedClassWeights=False, useLabelEncoding=False, name='RandomForest', model='RandomForestClassifier(min_samples_leaf=2, random_state=42)']
INFO  2026-02-24 20:07:40,692 sensai.evaluation.crossval:eval_model:201 - Evaluation result for class, fold 2/10: ClassificationEvalStats[accuracy=1.0, balancedAccuracy=1.0, geoMeanTrueClassProb=0.9734228107223192, N=15]
INFO  2026-02-24 20:07:40,693 sensai.evaluation.crossval:eval_model:192 - Training and evaluating model with fold 3/10 ...
INFO  2026-02-24 20:07:40,694 sensai.vector_model:fit:359 - Fitting SkLearnRandomForestVectorClassificationModel instance
INFO  2026-02-24 20:07:40,695 sensai.sklearn.sklearn_base:_fit_classifier:314 - Fitting sklearn classifier of type RandomForestClassifier
INFO  2026-02-24 20:07:40,796 sensai.vector_model:fit:388 - Fitting completed in 0.10 seconds: SkLearnRandomForestVectorClassificationModel[featureGenerator=None, rawInputTransformerChain=DataFrameTransformerChain[dataFrameTransformers=[]], featureTransformerChain=DataFrameTransformerChain[dataFrameTransformers=[]], fitArgs={}, useBalancedClassWeights=False, useLabelEncoding=False, name='RandomForest', model='RandomForestClassifier(min_samples_leaf=2, random_state=42)']
INFO  2026-02-24 20:07:40,807 sensai.evaluation.crossval:eval_model:201 - Evaluation result for class, fold 3/10: ClassificationEvalStats[accuracy=1.0, balancedAccuracy=1.0, geoMeanTrueClassProb=0.976458969438705, N=15]
INFO  2026-02-24 20:07:40,808 sensai.evaluation.crossval:eval_model:192 - Training and evaluating model with fold 4/10 ...
INFO  2026-02-24 20:07:40,809 sensai.vector_model:fit:359 - Fitting SkLearnRandomForestVectorClassificationModel instance
INFO  2026-02-24 20:07:40,810 sensai.sklearn.sklearn_base:_fit_classifier:314 - Fitting sklearn classifier of type RandomForestClassifier
INFO  2026-02-24 20:07:40,913 sensai.vector_model:fit:388 - Fitting completed in 0.10 seconds: SkLearnRandomForestVectorClassificationModel[featureGenerator=None, rawInputTransformerChain=DataFrameTransformerChain[dataFrameTransformers=[]], featureTransformerChain=DataFrameTransformerChain[dataFrameTransformers=[]], fitArgs={}, useBalancedClassWeights=False, useLabelEncoding=False, name='RandomForest', model='RandomForestClassifier(min_samples_leaf=2, random_state=42)']
INFO  2026-02-24 20:07:40,924 sensai.evaluation.crossval:eval_model:201 - Evaluation result for class, fold 4/10: ClassificationEvalStats[accuracy=0.9333333333333333, balancedAccuracy=0.9333333333333332, geoMeanTrueClassProb=0.9411926691126593, N=15]
INFO  2026-02-24 20:07:40,925 sensai.evaluation.crossval:eval_model:192 - Training and evaluating model with fold 5/10 ...
INFO  2026-02-24 20:07:40,925 sensai.vector_model:fit:359 - Fitting SkLearnRandomForestVectorClassificationModel instance
INFO  2026-02-24 20:07:40,926 sensai.sklearn.sklearn_base:_fit_classifier:314 - Fitting sklearn classifier of type RandomForestClassifier
INFO  2026-02-24 20:07:41,028 sensai.vector_model:fit:388 - Fitting completed in 0.10 seconds: SkLearnRandomForestVectorClassificationModel[featureGenerator=None, rawInputTransformerChain=DataFrameTransformerChain[dataFrameTransformers=[]], featureTransformerChain=DataFrameTransformerChain[dataFrameTransformers=[]], fitArgs={}, useBalancedClassWeights=False, useLabelEncoding=False, name='RandomForest', model='RandomForestClassifier(min_samples_leaf=2, random_state=42)']
INFO  2026-02-24 20:07:41,040 sensai.evaluation.crossval:eval_model:201 - Evaluation result for class, fold 5/10: ClassificationEvalStats[accuracy=1.0, balancedAccuracy=1.0, geoMeanTrueClassProb=0.9298964965102043, N=15]
INFO  2026-02-24 20:07:41,040 sensai.evaluation.crossval:eval_model:192 - Training and evaluating model with fold 6/10 ...
INFO  2026-02-24 20:07:41,041 sensai.vector_model:fit:359 - Fitting SkLearnRandomForestVectorClassificationModel instance
INFO  2026-02-24 20:07:41,042 sensai.sklearn.sklearn_base:_fit_classifier:314 - Fitting sklearn classifier of type RandomForestClassifier
INFO  2026-02-24 20:07:41,145 sensai.vector_model:fit:388 - Fitting completed in 0.10 seconds: SkLearnRandomForestVectorClassificationModel[featureGenerator=None, rawInputTransformerChain=DataFrameTransformerChain[dataFrameTransformers=[]], featureTransformerChain=DataFrameTransformerChain[dataFrameTransformers=[]], fitArgs={}, useBalancedClassWeights=False, useLabelEncoding=False, name='RandomForest', model='RandomForestClassifier(min_samples_leaf=2, random_state=42)']
INFO  2026-02-24 20:07:41,156 sensai.evaluation.crossval:eval_model:201 - Evaluation result for class, fold 6/10: ClassificationEvalStats[accuracy=0.8666666666666667, balancedAccuracy=0.8888888888888888, geoMeanTrueClassProb=0.6379522029160006, N=15]
INFO  2026-02-24 20:07:41,156 sensai.evaluation.crossval:eval_model:192 - Training and evaluating model with fold 7/10 ...
INFO  2026-02-24 20:07:41,157 sensai.vector_model:fit:359 - Fitting SkLearnRandomForestVectorClassificationModel instance
INFO  2026-02-24 20:07:41,158 sensai.sklearn.sklearn_base:_fit_classifier:314 - Fitting sklearn classifier of type RandomForestClassifier
INFO  2026-02-24 20:07:41,259 sensai.vector_model:fit:388 - Fitting completed in 0.10 seconds: SkLearnRandomForestVectorClassificationModel[featureGenerator=None, rawInputTransformerChain=DataFrameTransformerChain[dataFrameTransformers=[]], featureTransformerChain=DataFrameTransformerChain[dataFrameTransformers=[]], fitArgs={}, useBalancedClassWeights=False, useLabelEncoding=False, name='RandomForest', model='RandomForestClassifier(min_samples_leaf=2, random_state=42)']
INFO  2026-02-24 20:07:41,270 sensai.evaluation.crossval:eval_model:201 - Evaluation result for class, fold 7/10: ClassificationEvalStats[accuracy=0.8666666666666667, balancedAccuracy=0.8611111111111112, geoMeanTrueClassProb=0.8099785263057822, N=15]
INFO  2026-02-24 20:07:41,270 sensai.evaluation.crossval:eval_model:192 - Training and evaluating model with fold 8/10 ...
INFO  2026-02-24 20:07:41,271 sensai.vector_model:fit:359 - Fitting SkLearnRandomForestVectorClassificationModel instance
INFO  2026-02-24 20:07:41,273 sensai.sklearn.sklearn_base:_fit_classifier:314 - Fitting sklearn classifier of type RandomForestClassifier
INFO  2026-02-24 20:07:41,374 sensai.vector_model:fit:388 - Fitting completed in 0.10 seconds: SkLearnRandomForestVectorClassificationModel[featureGenerator=None, rawInputTransformerChain=DataFrameTransformerChain[dataFrameTransformers=[]], featureTransformerChain=DataFrameTransformerChain[dataFrameTransformers=[]], fitArgs={}, useBalancedClassWeights=False, useLabelEncoding=False, name='RandomForest', model='RandomForestClassifier(min_samples_leaf=2, random_state=42)']
INFO  2026-02-24 20:07:41,388 sensai.evaluation.crossval:eval_model:201 - Evaluation result for class, fold 8/10: ClassificationEvalStats[accuracy=1.0, balancedAccuracy=1.0, geoMeanTrueClassProb=0.9657414983648998, N=15]
INFO  2026-02-24 20:07:41,389 sensai.evaluation.crossval:eval_model:192 - Training and evaluating model with fold 9/10 ...
INFO  2026-02-24 20:07:41,390 sensai.vector_model:fit:359 - Fitting SkLearnRandomForestVectorClassificationModel instance
INFO  2026-02-24 20:07:41,392 sensai.sklearn.sklearn_base:_fit_classifier:314 - Fitting sklearn classifier of type RandomForestClassifier
INFO  2026-02-24 20:07:41,495 sensai.vector_model:fit:388 - Fitting completed in 0.10 seconds: SkLearnRandomForestVectorClassificationModel[featureGenerator=None, rawInputTransformerChain=DataFrameTransformerChain[dataFrameTransformers=[]], featureTransformerChain=DataFrameTransformerChain[dataFrameTransformers=[]], fitArgs={}, useBalancedClassWeights=False, useLabelEncoding=False, name='RandomForest', model='RandomForestClassifier(min_samples_leaf=2, random_state=42)']
INFO  2026-02-24 20:07:41,508 sensai.evaluation.crossval:eval_model:201 - Evaluation result for class, fold 9/10: ClassificationEvalStats[accuracy=1.0, balancedAccuracy=1.0, geoMeanTrueClassProb=0.9560552426688266, N=15]
INFO  2026-02-24 20:07:41,509 sensai.evaluation.crossval:eval_model:192 - Training and evaluating model with fold 10/10 ...
INFO  2026-02-24 20:07:41,509 sensai.vector_model:fit:359 - Fitting SkLearnRandomForestVectorClassificationModel instance
INFO  2026-02-24 20:07:41,511 sensai.sklearn.sklearn_base:_fit_classifier:314 - Fitting sklearn classifier of type RandomForestClassifier
INFO  2026-02-24 20:07:41,613 sensai.vector_model:fit:388 - Fitting completed in 0.10 seconds: SkLearnRandomForestVectorClassificationModel[featureGenerator=None, rawInputTransformerChain=DataFrameTransformerChain[dataFrameTransformers=[]], featureTransformerChain=DataFrameTransformerChain[dataFrameTransformers=[]], fitArgs={}, useBalancedClassWeights=False, useLabelEncoding=False, name='RandomForest', model='RandomForestClassifier(min_samples_leaf=2, random_state=42)']
INFO  2026-02-24 20:07:41,625 sensai.evaluation.crossval:eval_model:201 - Evaluation result for class, fold 10/10: ClassificationEvalStats[accuracy=0.9333333333333333, balancedAccuracy=0.9523809523809524, geoMeanTrueClassProb=0.841736920530503, N=15]
INFO  2026-02-24 20:07:41,642 sensai.evaluation.eval_util:perform_cross_validation:351 - Cross-validation results:
       mean[accuracy]  std[accuracy]  mean[balancedAccuracy]  std[balancedAccuracy]  mean[geoMeanTrueClassProb]  std[geoMeanTrueClassProb]
class            0.96       0.053333                0.963571               0.050077                     0.89878                    0.10223
INFO  2026-02-24 20:07:41,719 sensai.evaluation.eval_util:compare_models:400 - Evaluating model 2/2 named 'DecisionTree' ...
INFO  2026-02-24 20:07:41,719 sensai.evaluation.crossval:eval_model:192 - Training and evaluating model with fold 1/10 ...
INFO  2026-02-24 20:07:41,720 sensai.vector_model:fit:359 - Fitting SkLearnDecisionTreeVectorClassificationModel instance
INFO  2026-02-24 20:07:41,722 sensai.sklearn.sklearn_base:_fit_classifier:314 - Fitting sklearn classifier of type DecisionTreeClassifier
INFO  2026-02-24 20:07:41,724 sensai.vector_model:fit:388 - Fitting completed in 0.00 seconds: SkLearnDecisionTreeVectorClassificationModel[featureGenerator=None, rawInputTransformerChain=DataFrameTransformerChain[dataFrameTransformers=[]], featureTransformerChain=DataFrameTransformerChain[dataFrameTransformers=[]], fitArgs={}, useBalancedClassWeights=False, useLabelEncoding=False, name='DecisionTree', model='DecisionTreeClassifier(min_samples_leaf=2, random_state=42)']
INFO  2026-02-24 20:07:41,731 sensai.evaluation.crossval:eval_model:201 - Evaluation result for class, fold 1/10: ClassificationEvalStats[accuracy=1.0, balancedAccuracy=1.0, geoMeanTrueClassProb=1.0, N=15]
INFO  2026-02-24 20:07:41,731 sensai.evaluation.crossval:eval_model:192 - Training and evaluating model with fold 2/10 ...
INFO  2026-02-24 20:07:41,732 sensai.vector_model:fit:359 - Fitting SkLearnDecisionTreeVectorClassificationModel instance
INFO  2026-02-24 20:07:41,733 sensai.sklearn.sklearn_base:_fit_classifier:314 - Fitting sklearn classifier of type DecisionTreeClassifier
INFO  2026-02-24 20:07:41,736 sensai.vector_model:fit:388 - Fitting completed in 0.00 seconds: SkLearnDecisionTreeVectorClassificationModel[featureGenerator=None, rawInputTransformerChain=DataFrameTransformerChain[dataFrameTransformers=[]], featureTransformerChain=DataFrameTransformerChain[dataFrameTransformers=[]], fitArgs={}, useBalancedClassWeights=False, useLabelEncoding=False, name='DecisionTree', model='DecisionTreeClassifier(min_samples_leaf=2, random_state=42)']
INFO  2026-02-24 20:07:41,742 sensai.evaluation.crossval:eval_model:201 - Evaluation result for class, fold 2/10: ClassificationEvalStats[accuracy=1.0, balancedAccuracy=1.0, geoMeanTrueClassProb=1.0, N=15]
INFO  2026-02-24 20:07:41,742 sensai.evaluation.crossval:eval_model:192 - Training and evaluating model with fold 3/10 ...
INFO  2026-02-24 20:07:41,743 sensai.vector_model:fit:359 - Fitting SkLearnDecisionTreeVectorClassificationModel instance
INFO  2026-02-24 20:07:41,744 sensai.sklearn.sklearn_base:_fit_classifier:314 - Fitting sklearn classifier of type DecisionTreeClassifier
INFO  2026-02-24 20:07:41,747 sensai.vector_model:fit:388 - Fitting completed in 0.00 seconds: SkLearnDecisionTreeVectorClassificationModel[featureGenerator=None, rawInputTransformerChain=DataFrameTransformerChain[dataFrameTransformers=[]], featureTransformerChain=DataFrameTransformerChain[dataFrameTransformers=[]], fitArgs={}, useBalancedClassWeights=False, useLabelEncoding=False, name='DecisionTree', model='DecisionTreeClassifier(min_samples_leaf=2, random_state=42)']
INFO  2026-02-24 20:07:41,753 sensai.evaluation.crossval:eval_model:201 - Evaluation result for class, fold 3/10: ClassificationEvalStats[accuracy=1.0, balancedAccuracy=1.0, geoMeanTrueClassProb=1.0, N=15]
INFO  2026-02-24 20:07:41,753 sensai.evaluation.crossval:eval_model:192 - Training and evaluating model with fold 4/10 ...
INFO  2026-02-24 20:07:41,754 sensai.vector_model:fit:359 - Fitting SkLearnDecisionTreeVectorClassificationModel instance
INFO  2026-02-24 20:07:41,755 sensai.sklearn.sklearn_base:_fit_classifier:314 - Fitting sklearn classifier of type DecisionTreeClassifier
INFO  2026-02-24 20:07:41,758 sensai.vector_model:fit:388 - Fitting completed in 0.00 seconds: SkLearnDecisionTreeVectorClassificationModel[featureGenerator=None, rawInputTransformerChain=DataFrameTransformerChain[dataFrameTransformers=[]], featureTransformerChain=DataFrameTransformerChain[dataFrameTransformers=[]], fitArgs={}, useBalancedClassWeights=False, useLabelEncoding=False, name='DecisionTree', model='DecisionTreeClassifier(min_samples_leaf=2, random_state=42)']
INFO  2026-02-24 20:07:41,764 sensai.evaluation.crossval:eval_model:201 - Evaluation result for class, fold 4/10: ClassificationEvalStats[accuracy=0.9333333333333333, balancedAccuracy=0.9333333333333332, geoMeanTrueClassProb=0.6141303814089187, N=15]
INFO  2026-02-24 20:07:41,764 sensai.evaluation.crossval:eval_model:192 - Training and evaluating model with fold 5/10 ...
INFO  2026-02-24 20:07:41,765 sensai.vector_model:fit:359 - Fitting SkLearnDecisionTreeVectorClassificationModel instance
INFO  2026-02-24 20:07:41,766 sensai.sklearn.sklearn_base:_fit_classifier:314 - Fitting sklearn classifier of type DecisionTreeClassifier
INFO  2026-02-24 20:07:41,769 sensai.vector_model:fit:388 - Fitting completed in 0.00 seconds: SkLearnDecisionTreeVectorClassificationModel[featureGenerator=None, rawInputTransformerChain=DataFrameTransformerChain[dataFrameTransformers=[]], featureTransformerChain=DataFrameTransformerChain[dataFrameTransformers=[]], fitArgs={}, useBalancedClassWeights=False, useLabelEncoding=False, name='DecisionTree', model='DecisionTreeClassifier(min_samples_leaf=2, random_state=42)']
INFO  2026-02-24 20:07:41,775 sensai.evaluation.crossval:eval_model:201 - Evaluation result for class, fold 5/10: ClassificationEvalStats[accuracy=0.9333333333333333, balancedAccuracy=0.9333333333333332, geoMeanTrueClassProb=0.9548416039104165, N=15]
INFO  2026-02-24 20:07:41,776 sensai.evaluation.crossval:eval_model:192 - Training and evaluating model with fold 6/10 ...
INFO  2026-02-24 20:07:41,776 sensai.vector_model:fit:359 - Fitting SkLearnDecisionTreeVectorClassificationModel instance
INFO  2026-02-24 20:07:41,777 sensai.sklearn.sklearn_base:_fit_classifier:314 - Fitting sklearn classifier of type DecisionTreeClassifier
INFO  2026-02-24 20:07:41,780 sensai.vector_model:fit:388 - Fitting completed in 0.00 seconds: SkLearnDecisionTreeVectorClassificationModel[featureGenerator=None, rawInputTransformerChain=DataFrameTransformerChain[dataFrameTransformers=[]], featureTransformerChain=DataFrameTransformerChain[dataFrameTransformers=[]], fitArgs={}, useBalancedClassWeights=False, useLabelEncoding=False, name='DecisionTree', model='DecisionTreeClassifier(min_samples_leaf=2, random_state=42)']
INFO  2026-02-24 20:07:41,785 sensai.evaluation.crossval:eval_model:201 - Evaluation result for class, fold 6/10: ClassificationEvalStats[accuracy=0.8666666666666667, balancedAccuracy=0.8888888888888888, geoMeanTrueClassProb=0.39810717055349726, N=15]
INFO  2026-02-24 20:07:41,786 sensai.evaluation.crossval:eval_model:192 - Training and evaluating model with fold 7/10 ...
INFO  2026-02-24 20:07:41,786 sensai.vector_model:fit:359 - Fitting SkLearnDecisionTreeVectorClassificationModel instance
INFO  2026-02-24 20:07:41,787 sensai.sklearn.sklearn_base:_fit_classifier:314 - Fitting sklearn classifier of type DecisionTreeClassifier
INFO  2026-02-24 20:07:41,791 sensai.vector_model:fit:388 - Fitting completed in 0.00 seconds: SkLearnDecisionTreeVectorClassificationModel[featureGenerator=None, rawInputTransformerChain=DataFrameTransformerChain[dataFrameTransformers=[]], featureTransformerChain=DataFrameTransformerChain[dataFrameTransformers=[]], fitArgs={}, useBalancedClassWeights=False, useLabelEncoding=False, name='DecisionTree', model='DecisionTreeClassifier(min_samples_leaf=2, random_state=42)']
INFO  2026-02-24 20:07:41,796 sensai.evaluation.crossval:eval_model:201 - Evaluation result for class, fold 7/10: ClassificationEvalStats[accuracy=0.8666666666666667, balancedAccuracy=0.8611111111111112, geoMeanTrueClassProb=0.39810717055349726, N=15]
INFO  2026-02-24 20:07:41,797 sensai.evaluation.crossval:eval_model:192 - Training and evaluating model with fold 8/10 ...
INFO  2026-02-24 20:07:41,798 sensai.vector_model:fit:359 - Fitting SkLearnDecisionTreeVectorClassificationModel instance
INFO  2026-02-24 20:07:41,799 sensai.sklearn.sklearn_base:_fit_classifier:314 - Fitting sklearn classifier of type DecisionTreeClassifier
INFO  2026-02-24 20:07:41,802 sensai.vector_model:fit:388 - Fitting completed in 0.00 seconds: SkLearnDecisionTreeVectorClassificationModel[featureGenerator=None, rawInputTransformerChain=DataFrameTransformerChain[dataFrameTransformers=[]], featureTransformerChain=DataFrameTransformerChain[dataFrameTransformers=[]], fitArgs={}, useBalancedClassWeights=False, useLabelEncoding=False, name='DecisionTree', model='DecisionTreeClassifier(min_samples_leaf=2, random_state=42)']
INFO  2026-02-24 20:07:41,807 sensai.evaluation.crossval:eval_model:201 - Evaluation result for class, fold 8/10: ClassificationEvalStats[accuracy=0.9333333333333333, balancedAccuracy=0.9444444444444445, geoMeanTrueClassProb=0.9548416039104165, N=15]
INFO  2026-02-24 20:07:41,808 sensai.evaluation.crossval:eval_model:192 - Training and evaluating model with fold 9/10 ...
INFO  2026-02-24 20:07:41,808 sensai.vector_model:fit:359 - Fitting SkLearnDecisionTreeVectorClassificationModel instance
INFO  2026-02-24 20:07:41,809 sensai.sklearn.sklearn_base:_fit_classifier:314 - Fitting sklearn classifier of type DecisionTreeClassifier
INFO  2026-02-24 20:07:41,812 sensai.vector_model:fit:388 - Fitting completed in 0.00 seconds: SkLearnDecisionTreeVectorClassificationModel[featureGenerator=None, rawInputTransformerChain=DataFrameTransformerChain[dataFrameTransformers=[]], featureTransformerChain=DataFrameTransformerChain[dataFrameTransformers=[]], fitArgs={}, useBalancedClassWeights=False, useLabelEncoding=False, name='DecisionTree', model='DecisionTreeClassifier(min_samples_leaf=2, random_state=42)']
INFO  2026-02-24 20:07:41,818 sensai.evaluation.crossval:eval_model:201 - Evaluation result for class, fold 9/10: ClassificationEvalStats[accuracy=0.9333333333333333, balancedAccuracy=0.9333333333333332, geoMeanTrueClassProb=0.6141303814089187, N=15]
INFO  2026-02-24 20:07:41,818 sensai.evaluation.crossval:eval_model:192 - Training and evaluating model with fold 10/10 ...
INFO  2026-02-24 20:07:41,819 sensai.vector_model:fit:359 - Fitting SkLearnDecisionTreeVectorClassificationModel instance
INFO  2026-02-24 20:07:41,820 sensai.sklearn.sklearn_base:_fit_classifier:314 - Fitting sklearn classifier of type DecisionTreeClassifier
INFO  2026-02-24 20:07:41,823 sensai.vector_model:fit:388 - Fitting completed in 0.00 seconds: SkLearnDecisionTreeVectorClassificationModel[featureGenerator=None, rawInputTransformerChain=DataFrameTransformerChain[dataFrameTransformers=[]], featureTransformerChain=DataFrameTransformerChain[dataFrameTransformers=[]], fitArgs={}, useBalancedClassWeights=False, useLabelEncoding=False, name='DecisionTree', model='DecisionTreeClassifier(min_samples_leaf=2, random_state=42)']
INFO  2026-02-24 20:07:41,829 sensai.evaluation.crossval:eval_model:201 - Evaluation result for class, fold 10/10: ClassificationEvalStats[accuracy=0.9333333333333333, balancedAccuracy=0.9523809523809524, geoMeanTrueClassProb=0.6309573444801932, N=15]
INFO  2026-02-24 20:07:41,845 sensai.evaluation.eval_util:perform_cross_validation:351 - Cross-validation results:
       mean[accuracy]  std[accuracy]  mean[balancedAccuracy]  std[balancedAccuracy]  mean[geoMeanTrueClassProb]  std[geoMeanTrueClassProb]
class            0.94       0.046667                0.944683                0.04441                    0.756512                   0.238693
INFO  2026-02-24 20:07:41,925 sensai.evaluation.eval_util:compare_models:469 - Model comparison results, aggregated across folds:
              mean[accuracy]  std[accuracy]  mean[balancedAccuracy]  std[balancedAccuracy]  mean[geoMeanTrueClassProb]  std[geoMeanTrueClassProb]
model_name                                                                                                                                       
RandomForest            0.96       0.053333                0.963571               0.050077                    0.898780                   0.102230
DecisionTree            0.94       0.046667                0.944683               0.044410                    0.756512                   0.238693

In addition to the data frame with the aggregated metrics, which was already printed to the log, the results object contains all the data that was generated during the evaluation. We can, for example, use it to plot the distribution of one of the metrics across all the folds for one of our models.

display(results.results_df)

esc_random_forest = results.result_by_model_name["RandomForest"].cross_validation_data.get_eval_stats_collection()
esc_random_forest.plot_distribution("accuracy", bins=np.linspace(0,1,21), stat="count", kde=False);
mean[accuracy] std[accuracy] mean[balancedAccuracy] std[balancedAccuracy] mean[geoMeanTrueClassProb] std[geoMeanTrueClassProb]
model_name
RandomForest 0.96 0.053333 0.963571 0.050077 0.898780 0.102230
DecisionTree 0.94 0.046667 0.944683 0.044410 0.756512 0.238693
../_images/6c289c3e2e82545fd4529bf141264e570bb51223fcb44913cb39be172fdb332b.png

We can also compute additional aggregations or inspect the full list of metrics.

esc_random_forest.agg_metrics_dict(agg_fns=[np.max, np.min])
{'max[accuracy]': 1.0,
 'min[accuracy]': 0.8666666666666667,
 'max[balancedAccuracy]': 1.0,
 'min[balancedAccuracy]': 0.8611111111111112,
 'max[geoMeanTrueClassProb]': 0.976458969438705,
 'min[geoMeanTrueClassProb]': 0.6379522029160006}
esc_random_forest.get_values("accuracy")
[1.0,
 1.0,
 1.0,
 0.9333333333333333,
 1.0,
 0.8666666666666667,
 0.8666666666666667,
 1.0,
 1.0,
 0.9333333333333333]

Feature Generators and Data Frame Transformers#

When dealing with the preparation of input data for a model, we often need to cater to technical requirements of various types of models. sensAI seeks to make the process of supporting multiple input pipelines for different types of models as simple as possible - by focusing on concise, declarative semantics and integrating the model-specific data extraction and transformation mechanisms into the models themselves. In essence, this means:

  1. Starting with the raw or most general representation of the data

    This could mean simply starting with the data that is straightforward for us to obtain - or using directly using particular domain specific objects.

    For example, if the problem is to classify situations, we might already have a Situation class in our code which represents all the data that is is relevant to a situation (e.g. the point in time, the affected user, the location, etc.). Pandas DataFrames can represent arbitrary data, so there is no reason to not simply use as the raw input data frame that is fed to our models a single column containing instances of class Situation. Or we might instead directly observe a set of sensor readings, all of which are real numbers; this scenario would certainly be closer to what we typically see in machine learning data sets, but it isn’t always the case in the real world.

    Whatever the case may be, we can represent it in a data frame. We call the original input data frame, which we pass to a sensAI VectorModel, the raw data frame.

  2. Extracting features from the raw data, using their “natural” representation (using FeatureGenerators)

    We extract from the raw data frame pieces of information that we regard as relevant features for the task at hand. A sensAI FeatureGenerator can generate one or more data frame columns (containing arbitrary data), and a model can be associated with any number of feature generators. Several key aspects:

    • FeatureGenerators crititcally decouple the original raw data from the features used by the models, enabling different models to use different sets of features or entirely different representations of the same features.

    • FeatureGenerators become part of the model and are (where necessary) jointly trained with the model. This facilitates model deployment, as every sensAI model becomes a single unit that can directly process raw input data, which is (usually) straightforward to supply at inference time.

    • FeatureGenerators store meta-data on the features they generate, enabling downstream components to handle them appropriately.

    The feature representation that we choose to generate can be arbitrary, but oftentimes, we will want to extract “natural” feature representations, which could, in priciple, be used by many types of models, albeit in different concrete forms. Sequential data can be naturally represented as an array/list, categorical data can be represented using descriptive category names, and numeric data can be represented using unmodified integers and floating point numbers.

  3. Transforming feature representations into a form that is suitable for the model at hand (using DataFrameTransformers)

    In the transformation stage, we address the model-specific idiosynchrasies, which may require, for example, that all features be represented as numbers (or even numbers within a limited range) or that all features be discrete, that no values be missing, etc. A DataFrameTransformer can, in principle perform an arbitary transformation from one data frame to another, but the typical use case is to apply transformations of feature representations that are necessary for specific types of models to work (their best).