Moved ChebyshevDistance into ArcadeDB project

engine/src/main/java/com/arcadedb/index/vector/distance/ChebyshevDistance.java

@@ -0,0 +1,69 @@
+/*
+ * Copyright 2023 Arcade Data Ltd
+ *
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+package com.arcadedb.index.vector.distance;
+
+import com.github.jelmerk.knn.DistanceFunction;
+
+/**
+ * Implementation of {@link DistanceFunction} that calculates the chebyshev distance.
+ *
+ * @author @gramian
+ */
+public class ChebyshevDistance {
+  public static class FloatChebyshevDistance implements DistanceFunction<float[], Float> {
+    /**
+     * Calculates the chebyshev distance.
+     *
+     * @param u Left vector.
+     * @param v Right vector.
+     *
+     * @return Chebyshev distance between u and v.
+     */
+    @Override
+    public Float distance(final float[] u, final float[] v) {
+      float max = 0.0F;
+      for (int i = 0; i < u.length; i++) {
+        max = Math.max(max, Math.abs(u[i] - v[i]));
+      }
+      return max;
+    }
+  }
+
+  public static class DoubleChebyshevDistance implements DistanceFunction<double[], Double> {
+    /**
+     * Calculates the chebyshev distance.
+     *
+     * @param u Left vector.
+     * @param v Right vector.
+     *
+     * @return Chebyshev distance between u and v.
+     */
+    @Override
+    public Double distance(final double[] u, final double[] v) {
+      double max = 0.0D;
+      for (int i = 0; i < u.length; i++) {
+        max = Math.max(max, Math.abs(u[i] - v[i]));
+      }
+      return max;
+    }
+  }
+}

engine/src/main/java/com/arcadedb/index/vector/DistanceFunctionFactory.java → engine/src/main/java/com/arcadedb/index/vector/distance/DistanceFunctionFactory.java

@@ -19,7 +19,7 @@
  * under the License.
  */
 
-package com.arcadedb.index.vector;
+package com.arcadedb.index.vector.distance;
 
 import com.github.jelmerk.knn.DistanceFunction;
 import com.github.jelmerk.knn.DistanceFunctions;
@@ -42,15 +42,15 @@ public class DistanceFunctionFactory {
     implementations.put("FloatBrayCurtisDistance", DistanceFunctions.FLOAT_BRAY_CURTIS_DISTANCE);
     implementations.put("FloatCorrelationDistance", DistanceFunctions.FLOAT_CORRELATION_DISTANCE);
     implementations.put("FloatManhattanDistance", DistanceFunctions.FLOAT_MANHATTAN_DISTANCE);
-    implementations.put("FloatChebyshevDistance", DistanceFunctions.FLOAT_CHEBYSHEV_DISTANCE);
+    implementations.put("FloatChebyshevDistance", new ChebyshevDistance.FloatChebyshevDistance());
     implementations.put("DoubleCosineDistance", DistanceFunctions.DOUBLE_COSINE_DISTANCE);
     implementations.put("DoubleInnerProduct", DistanceFunctions.DOUBLE_INNER_PRODUCT);
     implementations.put("DoubleEuclideanDistance", DistanceFunctions.DOUBLE_EUCLIDEAN_DISTANCE);
     implementations.put("DoubleCanberraDistance", DistanceFunctions.DOUBLE_CANBERRA_DISTANCE);
     implementations.put("DoubleBrayCurtisDistance", DistanceFunctions.DOUBLE_BRAY_CURTIS_DISTANCE);
     implementations.put("DoubleCorrelationDistance", DistanceFunctions.DOUBLE_CORRELATION_DISTANCE);
     implementations.put("DoubleManhattanDistance", DistanceFunctions.DOUBLE_MANHATTAN_DISTANCE);
-    implementations.put("DoubleChebyshevDistance", DistanceFunctions.DOUBLE_CHEBYSHEV_DISTANCE);
+    implementations.put("DoubleChebyshevDistance", new ChebyshevDistance.DoubleChebyshevDistance());
     implementations.put("FloatSparseVectorInnerProduct", DistanceFunctions.FLOAT_SPARSE_VECTOR_INNER_PRODUCT);
     implementations.put("DoubleSparseVectorInnerProduct", DistanceFunctions.DOUBLE_SPARSE_VECTOR_INNER_PRODUCT);
   }