m2cgen
m2cgen (Model 2 Code Generator) - is a lightweight library which provides an easy way to transpile trained statistical models into a native code (Python, C, Java).
Installation
pip install m2cgen
Supported Languages
- Python
- Java
- C
Supported Models
| Classification | Regression | |
|---|---|---|
| Linear | LogisticRegression, LogisticRegressionCV, RidgeClassifier, RidgeClassifierCV, SGDClassifier, PassiveAggressiveClassifier | LinearRegression, HuberRegressor, ElasticNet, ElasticNetCV, TheilSenRegressor, Lars, LarsCV, Lasso, LassoCV, LassoLars, LassoLarsIC, OrthogonalMatchingPursuit, OrthogonalMatchingPursuitCV, Ridge, RidgeCV, BayesianRidge, ARDRegression, SGDRegressor, PassiveAggressiveRegressor |
| SVM | LinearSVC | LinearSVR |
| Tree | DecisionTreeClassifier, ExtraTreeClassifier | DecisionTreeRegressor, ExtraTreeRegressor |
| Random Forest | RandomForestClassifier, ExtraTreesClassifier | RandomForestRegressor, ExtraTreesRegressor |
| Boosting | XGBClassifier(gbtree/dart booster only), LGBMClassifier(gbdt/dart booster only) | XGBRegressor(gbtree/dart booster only), LGBMRegressor(gbdt/dart booster only) |
Classification Output
| Binary | Multiclass | Comment | |
|---|---|---|---|
| Linear | Scalar value; signed distance of the sample to the hyperplane for the second class | Vector value; signed distance of the sample to the hyperplane per each class | The output is consistent with the output of LinearClassifierMixin.decision_function |
| Tree/Random Forest/XGBoost/LightGBM | Vector value; class probabilities | Vector value; class probabilities | The output is consistent with the output of the predict_proba method of DecisionTreeClassifier/ForestClassifier/XGBClassifier/LGBMClassifier |
Usage
Here's a simple example of how a trained linear model can be represented in Java code:
from sklearn.datasets import load_boston
from sklearn import linear_model
import m2cgen as m2c
boston = load_boston()
X, y = boston.data, boston.target
estimator = linear_model.LinearRegression()
estimator.fit(X, y)
code = m2c.export_to_java(estimator)The example of the generated code:
public class Model {
public static double score(double[] input) {
return (((((((((((((36.45948838508965) + ((input[0]) * (-0.10801135783679647))) + ((input[1]) * (0.04642045836688297))) + ((input[2]) * (0.020558626367073608))) + ((input[3]) * (2.6867338193449406))) + ((input[4]) * (-17.76661122830004))) + ((input[5]) * (3.8098652068092163))) + ((input[6]) * (0.0006922246403454562))) + ((input[7]) * (-1.475566845600257))) + ((input[8]) * (0.30604947898516943))) + ((input[9]) * (-0.012334593916574394))) + ((input[10]) * (-0.9527472317072884))) + ((input[11]) * (0.009311683273794044))) + ((input[12]) * (-0.5247583778554867));
}
}You can find more examples of generated code for different models/languages here
CLI
m2cgen can be used as a CLI tool to generate code using serialized model objects (pickle protocol):
$ m2cgen <pickle_file> --language <language> [--indent <indent>]
[--class_name <class_name>] [--package_name <package_name>]
[--recursion-limit <recursion_limit>]
Piping is also supported:
$ cat <pickle_file> | m2cgen --language <language>
FAQ
Q: Generation fails with RuntimeError: maximum recursion depth exceeded error.
A: If this error occurs while generating code using an ensemble model, try to reduce the number of trained estimators within that model. Alternatively you can increase the maximum recursion depth with sys.setrecursionlimit(<new_depth>).