Apache Flink ML Library

import org.apache.flink.ml.common.MLEnvironment;
import org.apache.flink.ml.common.linalg.DenseVector;
import org.apache.flink.ml.common.linalg.DenseMatrix;
import org.apache.flink.ml.pipeline.EstimatorBase;
import org.apache.flink.ml.pipeline.TransformerBase;

import org.apache.flink.ml.common.MLEnvironment;
import org.apache.flink.ml.common.linalg.DenseVector;
import org.apache.flink.ml.common.linalg.DenseMatrix;
import org.apache.flink.api.java.ExecutionEnvironment;
import org.apache.flink.table.api.bridge.java.BatchTableEnvironment;

// Set up ML environment
ExecutionEnvironment env = ExecutionEnvironment.getExecutionEnvironment();
BatchTableEnvironment tableEnv = BatchTableEnvironment.create(env);
MLEnvironment mlEnv = new MLEnvironment(env, tableEnv);

// Create and manipulate vectors
DenseVector vector1 = new DenseVector(new double[]{1.0, 2.0, 3.0});
DenseVector vector2 = new DenseVector(new double[]{4.0, 5.0, 6.0});
DenseVector result = vector1.plus(vector2);

// Create and manipulate matrices
DenseMatrix matrix = DenseMatrix.eye(3);
DenseVector matrixResult = matrix.multiplies(vector1);

// Use in ML pipeline
// EstimatorBase and TransformerBase provide foundation for ML algorithms

public class MLEnvironment {
    public MLEnvironment();
    public MLEnvironment(ExecutionEnvironment batchEnv, BatchTableEnvironment batchTableEnv);
    public MLEnvironment(StreamExecutionEnvironment streamEnv, StreamTableEnvironment streamTableEnv);
    public ExecutionEnvironment getExecutionEnvironment();
    public StreamExecutionEnvironment getStreamExecutionEnvironment();
    public BatchTableEnvironment getBatchTableEnvironment();
    public StreamTableEnvironment getStreamTableEnvironment();
}

public class MLEnvironmentFactory {
    public static MLEnvironment get(Long mlEnvId);
    public static MLEnvironment getDefault();
    public static Long getNewMLEnvironmentId();
    public static Long registerMLEnvironment(MLEnvironment env);
}

public abstract class Vector implements Serializable {
    public abstract int size();
    public abstract double get(int i);
    public abstract void set(int i, double val);
    public abstract double normL1();
    public abstract double normL2();
    public abstract Vector scale(double v);
    public abstract Vector plus(Vector vec);
    public abstract Vector minus(Vector vec);
    public abstract double dot(Vector vec);
}

public class DenseVector extends Vector {
    public DenseVector(double[] data);
    public static DenseVector ones(int n);
    public static DenseVector zeros(int n);
    public static DenseVector rand(int n);
    public double[] getData();
}

public class DenseMatrix implements Serializable {
    public DenseMatrix(int m, int n);
    public DenseMatrix(double[][] data);
    public static DenseMatrix eye(int n);
    public static DenseMatrix zeros(int m, int n);
    public DenseVector multiplies(DenseVector x);
    public DenseMatrix multiplies(DenseMatrix mat);
}

public abstract class EstimatorBase<E extends EstimatorBase<E, M>, M extends ModelBase<M>> 
    extends PipelineStageBase<E> implements Estimator<E, M> {
    public M fit(Table input);
    public M fit(TableEnvironment tEnv, Table input);
}

public abstract class TransformerBase<T extends TransformerBase<T>> 
    extends PipelineStageBase<T> implements Transformer<T> {
    public Table transform(Table input);
    public Table transform(TableEnvironment tEnv, Table input);
}

public abstract class ModelBase<M extends ModelBase<M>> 
    extends TransformerBase<M> implements Model<M> {
    public Table getModelData();
    public M setModelData(Table modelData);
}

public abstract class AlgoOperator<T extends AlgoOperator<T>> 
    implements WithParams<T>, HasMLEnvironmentId<T>, Serializable {
    public Table getOutput();
    public Table[] getSideOutputs();
    public String[] getColNames();
    public TypeInformation<?>[] getColTypes();
    public TableSchema getSchema();
}

public abstract class BatchOperator<T extends BatchOperator<T>> extends AlgoOperator<T> {
    public <B extends BatchOperator<?>> B link(B next);
    public abstract T linkFrom(BatchOperator<?>... inputs);
    public static BatchOperator<?> fromTable(Table table);
}

public class TableUtil {
    public static int findColIndex(String[] tableCols, String targetCol);
    public static int[] findColIndices(TableSchema tableSchema, String[] targetCols);
    public static TypeInformation<?> findColType(TableSchema tableSchema, String targetCol);
    public static void assertSelectedColExist(String[] tableCols, String... selectedCols);
    public static void assertNumericalCols(TableSchema tableSchema, String... selectedCols);
    public static String[] getStringCols(TableSchema tableSchema);
    public static String[] getNumericCols(TableSchema tableSchema);
}

public class VectorTypes {
    public static final TypeInformation<DenseVector> DENSE_VECTOR;
    public static final TypeInformation<SparseVector> SPARSE_VECTOR;
    public static final TypeInformation<Vector> VECTOR;
}

public class MultivariateGaussian {
    public MultivariateGaussian(DenseVector mean, DenseMatrix cov);
    public double pdf(Vector x);
    public double logpdf(Vector x);
}

// Parameter interfaces for column management
public interface HasMLEnvironmentId<T> extends WithParams<T> {
    default Long getMLEnvironmentId();
    default T setMLEnvironmentId(Long value);
}

public interface HasOutputCol<T> extends WithParams<T> {
    default String getOutputCol();
    default T setOutputCol(String value);
}

public interface HasSelectedCols<T> extends WithParams<T> {
    default String[] getSelectedCols();
    default T setSelectedCols(String[] value);
}

// Vector iterator interface
public interface VectorIterator extends Serializable {
    boolean hasNext();
    void next();
    int getIndex();
    double getValue();
}

// Mapper interfaces
public abstract class Mapper implements Serializable {
    public Mapper(TableSchema dataSchema, Params params);
    public abstract Row map(Row row);
    public abstract TableSchema getOutputSchema();
}

// Model source interface
public interface ModelSource extends Serializable {
    List<Row> getModelRows(RuntimeContext runtimeContext);
}