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Scikit-learn Model Predict

Predict responses using pretrained Python scikit-learn model

Since R2024a

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  • Scikit-learn Model Predict Block Icon

Libraries:
Statistics and Machine Learning Toolbox / Python Models

Description

The Scikit-learn Model Predict block predicts responses using a pretrained Python® scikit-learn® model running in the MATLAB® Python environment. MATLAB supports the reference implementation of Python, often called CPython. If you use a Mac or Linux® platform, you already have Python installed. If you use Windows®, you need to install a distribution, such as those found at https://www.python.org/downloads/. For more information, see Configure Your System to Use Python. Your MATLAB Python environment must have the scikit-learn module installed. The Scikit-learn Model Predict block has been tested using Python version 3.10 and scikit-learn version 1.2.0.

Load a Python model into the block by specifying the path to a scikit-learn model file. You can optionally load a Python function to preprocess the observations (predictor data) that Simulink® passes to the Python model, and a Python function to postprocess the predicted responses from the model.

The input port x receives observations, optionally rearranges the input array dimensions, and then converts the observations to a Python array. The preprocessing function (if specified) processes the converted observations in Python and passes them to the Python model. The model generates predicted responses for the observations in Python and passes the responses to the Python postprocessing function (if specified). The output port Out1 returns the predicted responses from the model.

Note

The Scikit-learn Model Predict block cannot be run in Rapid Accelerator mode.

Examples

Predict Cluster Assignments Using Python Scikit-learn Model Predict Block

Predict Cluster Assignments Using Python Scikit-learn Model Predict Block

Use the Scikit-learn Model Predict block for prediction in Simulink®. The block accepts observations (predictor data), and returns the predicted cluster assignments using a trained unsupervised machine learning model that is executed in Python®. MATLAB® supports the reference implementation of Python, often called CPython. If you use a Mac or Linux® platform, you already have Python installed. If you use Windows®, you need to install a distribution, such as those found at https://www.python.org/downloads/. For more information, see Configure Your System to Use Python. Your MATLAB Python environment must have the scikit-learn module installed.

Ports

Input

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Predictor data, specified as a numeric matrix. By default, the rows correspond to observations, and the columns correspond to predictor variables. You can rearrange the dimensions of the predictor data that the software passes to the Python model by specifying a permutation vector on the Input tab of the Block Parameters dialog box (see Input).

Data Types: single | double | half | int8 | int16 | int32 | int64 | uint8 | uint16 | uint32 | uint64 | Boolean | fixed point

Output

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Predicted responses, returned as a numeric vector.

Data Types: single | double | half | int8 | int16 | int32 | int64 | uint8 | uint16 | uint32 | uint64 | Boolean

Parameters

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To edit block parameters interactively, use the Property Inspector. From the Simulink Toolstrip, on the Simulation tab, in the Prepare gallery, select Property Inspector.

Specify model file

Specify the name or path of a Python scikit-learn model file, or click the Browse button. You must save the model in Python using pickle.dumps(), joblib.dump(), or skops.io.dumps() (see https://scikit-learn.org/stable/model_persistence.html and https://pypi.org/project/skops/). The model must support a corresponding predict() method in Python. For more information, see https://scikit-learn.org/stable/.

Programmatic Use

Block Parameter: ModelFile
Type: character vector
Values: Python file | path to Python file
Default: "untitled"

Specify the discrete interval between sample time hits or specify another type of sample time, such as continuous (0) or inherited (–1). For more options, see Types of Sample Time (Simulink).

By default, the Scikit-learn Model Predict block inherits sample time based on the context of the block within the model.

Programmatic Use

Block Parameter: SampleTime
Type: string scalar or character vector
Values: scalar
Default: "–1"

Input

Input port properties, specified as a table. The table has the following columns:

  • Input Name — Block input port label, specified as a character vector. The block does not pass the input port label to the Python model.

  • Python Datatype — Python or NumPy datatype to which the Scikit-learn Model Predict block converts incoming data before passing it to Python, specified as a character vector. The block supports the Python numeric datatypes "int" and "float", and the NumPy numeric datatypes "float16", "float32", "float64", "int8", "uint8", "int16", "uint16", "int32", "uint32", "int64", and "uint64". The default value is "float32".

  • Permutation to Python — New dimension arrangement for the input data, specified as a numeric vector with unique positive integer elements that represent the dimensions of x (see permute). You can specify [2 1] to switch the row and column dimensions of x. The Scikit-learn Model Predict block passes the rearranged array to the Python model.

Programmatic Use

Block Parameter: InputTable
Type: cell array

Output

Output port properties, specified as a table. The table has the following columns:

  • Output Name — Label for the Scikit-learn Model Predict block output port, specified as a character vector.

  • Max Batch Size — Maximum batch size of the output, specified as a positive integer. Specify this parameter only if your Python model is capable of returning variable-sized output during a single simulation run.

Programmatic Use

Block Parameter: OutputTable
Type: cell array

Pre/Post-processing

Specify the name or path of a file defining an optional Python preprocessing function for the input data, or click the Browse button. When the Scikit-learn Model Predict receives observations, it converts them to a NumPy array. The preprocessing function processes the converted observations in Python and passes them to the Python model.

The preprocessing file must define a Python function with the signature 

outputList = preprocess(model,inputList)
where outputList and inputList are lists of NumPy ndarray objects of length 1, and model is the model object. The preprocessing file can be the same as the postprocessing file specified by Path to Python file defining postprocess() if the file contains both defining functions.

Programmatic Use

Block Parameter: PreprocessingFilePath
Type: character vector
Values: Python file | path to Python file

Specify the name or path of a file defining an optional Python postprocessing function for the output data, or click the Browse button. The Scikit-learn Model Predict block processes the output data from the Python model using the Python function and outputs it from the block.

The postprocessing file must define a Python function with the signature

outputList = postprocess(model,inputList)
where outputList and inputList are lists of NumPy ndarray objects, and model is the model object. The postprocessing file can be the same as the preprocessing file specified by Path to Python file defining preprocess() if the file contains both defining functions.

Programmatic Use

Block Parameter: PostprocessingFilePath
Type: character vector
Values: Python file | path to Python file

Block Characteristics

Data Types

Boolean | double | enumerated | fixed point | half | integer | single

Direct Feedthrough

yes

Multidimensional Signals

no

Variable-Size Signals

no

Zero-Crossing Detection

no

Version History

Introduced in R2024a

See Also

Blocks

External Websites