Added support for the 'lgb.Booster' model type. Fixes jpmml/r2pmml#75

README.md

@@ -50,6 +50,8 @@ Java library and command-line application for converting [R](https://www.r-proje
     * `cv.glmnet` - Cross-validated GLMNet regression and calculation
   * [`IsolationForest`](https://r-forge.r-project.org/R/?group_id=479) package:
     * `iForest` - Isolation Forest (IF) anomaly detection
+  * [`lightgbm`](https://cran.r-project.org/package=lightgbm) package:
+    * `lgb.Booster` - LightGBM regression and classification.
   * [`mlr`](https://cran.r-project.org/package=mlr) package:
     * `WrappedModel` - Selected JPMML-R model types.
   * [`neuralnet`](https://cran.r-project.org/package=neuralnet) package:

pmml-rexp-example/pom.xml

@@ -28,6 +28,10 @@
 			<groupId>org.jpmml</groupId>
 			<artifactId>pmml-rexp</artifactId>
 		</dependency>
+		<dependency>
+			<groupId>org.jpmml</groupId>
+			<artifactId>pmml-rexp-lightgbm</artifactId>
+		</dependency>
 		<dependency>
 			<groupId>org.jpmml</groupId>
 			<artifactId>pmml-rexp-xgboost</artifactId>

pmml-rexp-lightgbm/pom.xml

@@ -0,0 +1,48 @@
+<?xml version="1.0" ?>
+<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+	<modelVersion>4.0.0</modelVersion>
+
+	<parent>
+		<groupId>org.jpmml</groupId>
+		<artifactId>jpmml-r</artifactId>
+		<version>1.6-SNAPSHOT</version>
+	</parent>
+
+	<groupId>org.jpmml</groupId>
+	<artifactId>pmml-rexp-lightgbm</artifactId>
+	<packaging>jar</packaging>
+
+	<name>JPMML R LightGBM converter</name>
+	<description>JPMML R LightGBM to PMML converter</description>
+
+	<licenses>
+		<license>
+			<name>GNU Affero General Public License (AGPL) version 3.0</name>
+			<url>http://www.gnu.org/licenses/agpl-3.0.html</url>
+			<distribution>repo</distribution>
+		</license>
+	</licenses>
+
+	<dependencies>
+		<dependency>
+			<groupId>org.jpmml</groupId>
+			<artifactId>pmml-rexp</artifactId>
+		</dependency>
+
+		<dependency>
+			<groupId>org.jpmml</groupId>
+			<artifactId>pmml-evaluator-testing</artifactId>
+			<scope>provided</scope>
+		</dependency>
+
+		<dependency>
+			<groupId>org.jpmml</groupId>
+			<artifactId>pmml-lightgbm</artifactId>
+		</dependency>
+
+		<dependency>
+			<groupId>junit</groupId>
+			<artifactId>junit</artifactId>
+		</dependency>
+	</dependencies>
+</project>

pmml-rexp-lightgbm/src/main/java/org/jpmml/rexp/lightgbm/LightGBMConverter.java

@@ -0,0 +1,59 @@
+/*
+ * Copyright (c) 2024 Villu Ruusmann
+ *
+ * This file is part of JPMML-R
+ *
+ * JPMML-R is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * JPMML-R is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with JPMML-R.  If not, see <http://www.gnu.org/licenses/>.
+ */
+package org.jpmml.rexp.lightgbm;
+
+import java.io.ByteArrayInputStream;
+import java.io.IOException;
+import java.io.InputStream;
+import java.util.Collections;
+
+import org.dmg.pmml.PMML;
+import org.jpmml.lightgbm.GBDT;
+import org.jpmml.lightgbm.LightGBMUtil;
+import org.jpmml.rexp.Converter;
+import org.jpmml.rexp.REnvironment;
+import org.jpmml.rexp.RExpEncoder;
+import org.jpmml.rexp.RRaw;
+
+public class LightGBMConverter extends Converter<REnvironment> {
+
+	public LightGBMConverter(REnvironment environment){
+		super(environment);
+	}
+
+	@Override
+	public PMML encodePMML(RExpEncoder encoder){
+		REnvironment environment = getObject();
+
+		RRaw raw = (RRaw)environment.findVariable("raw");
+		if(raw == null){
+			throw new IllegalArgumentException();
+		}
+
+		GBDT gbdt;
+
+		try(InputStream is = new ByteArrayInputStream(raw.getValue())){
+			gbdt = LightGBMUtil.loadGBDT(is);
+		} catch(IOException ioe){
+			throw new IllegalArgumentException(ioe);
+		}
+
+		return gbdt.encodePMML(Collections.emptyMap(), null, null);
+	}
+}

pmml-rexp-lightgbm/src/main/resources/META-INF/r2pmml.properties

@@ -0,0 +1 @@
+lgb.Booster = org.jpmml.rexp.lightgbm.LightGBMConverter

pmml-rexp-lightgbm/src/test/R/lightgbm.R

@@ -0,0 +1,51 @@
+library("lightgbm")
+
+source("util.R")
+
+auto = loadAutoCsv("Auto")
+
+auto_X = auto[, -ncol(auto)]
+auto_y = auto[, ncol(auto)]
+
+auto.matrix = as.matrix(auto_X)
+
+auto.dset = lgb.Dataset(auto.matrix, label = auto_y)
+
+generateLightGBMAuto = function(){
+	auto.lgbm = lgb.train(params = list(objective = "regression"), data = auto.dset, nrounds = 31)
+
+	mpg = predict(auto.lgbm, auto.matrix)
+
+	storeRds(auto.lgbm, "LightGBMAuto")
+	storeCsv(data.frame("_target" = mpg), "LightGBMAuto")
+}
+
+set.seed(42)
+
+generateLightGBMAuto()
+
+iris = loadIrisCsv("Iris")
+
+iris_X = iris[, -ncol(iris)]
+iris_y = iris[, ncol(iris)]
+
+# Convert from factor to integer[0, num_class]
+iris_y = (as.integer(iris_y) - 1)
+
+iris.matrix = as.matrix(iris_X)
+
+iris.dset = lgb.Dataset(iris.matrix, label = iris_y)
+
+generateLightGBMIris = function(){
+	iris.lgbm = lgb.train(params = list(objective = "multiclass", num_class = 3, max_depth = 3), data = iris.dset, nrounds = 5)
+
+	probabilities = predict(iris.lgbm, iris.matrix)
+	species = max.col(probabilities) - 1
+
+	storeRds(iris.lgbm, "LightGBMIris")
+	storeCsv(data.frame("_target" = species, "probability(0)" = probabilities[, 1], "probability(1)" = probabilities[, 2], "probability(2)" = probabilities[, 3], check.names = FALSE), "LightGBMIris")
+}
+
+set.seed(42)
+
+generateLightGBMIris()

pmml-rexp-lightgbm/src/test/R/util.R

@@ -0,0 +1 @@
+source("../../../../pmml-rexp/src/test/R/util.R")

pmml-rexp-lightgbm/src/test/java/org/jpmml/rexp/lightgbm/testing/LightGBMConverterTest.java

@@ -0,0 +1,40 @@
+/*
+ * Copyright (c) 2024 Villu Ruusmann
+ *
+ * This file is part of JPMML-R
+ *
+ * JPMML-R is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * JPMML-R is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with JPMML-R.  If not, see <http://www.gnu.org/licenses/>.
+ */
+package org.jpmml.rexp.lightgbm.testing;
+
+import org.jpmml.converter.testing.Datasets;
+import org.jpmml.rexp.testing.RExpEncoderBatchTest;
+import org.junit.Test;
+
+public class LightGBMConverterTest extends RExpEncoderBatchTest implements Datasets {
+
+	public LightGBMConverterTest(){
+		super();
+	}
+
+	@Test
+	public void evaluateAuto() throws Exception {
+		evaluate("LightGBM", AUTO);
+	}
+
+	@Test
+	public void evaluateIris() throws Exception {
+		evaluate("LightGBM", IRIS);
+	}
+}