Adding the join method to the Array class (#27)

Author: Oscar Torreno

pom.xml

@@ -6,7 +6,7 @@
     </properties>
     <groupId>io.shapelets</groupId>
     <artifactId>khiva</artifactId>
-    <version>0.2.0</version>
+    <version>0.2.2</version>
 
     <name>khiva-java</name>
     <url>https://github.com/shapelets/khiva-java</url>

src/main/java/io/shapelets/khiva/Array.java

@@ -256,6 +256,8 @@ public Array(Array other) {
 
     private native long[] nativeGetDims();
 
+    private native int nativeGetType();
+
     private native long nativePrint();
 
     private native DoubleComplex[] getDoubleComplexFromArray();
@@ -276,7 +278,7 @@ public Array(Array other) {
 
     private native long[] getLongFromArray();
 
-    private native int nativeGetType();
+    private native long[] join(int dim, long refRhs);
 
     private native long[] add(long refRhs);
 
@@ -434,6 +436,19 @@ public long[] getDims() {
         return nativeGetDims();
     }
 
+    /**
+     * Joins this array with the one specified as parameter along the specified dimension.
+     *
+     * @param dim The dimension along which the join occurs.
+     * @param rhs Right-hand side array for the operation.
+     * @return The result of joining the given arrays along the specified dimension.
+     */
+    public Array join(int dim, Array rhs) {
+        long[] refs = join(dim, rhs.reference);
+        rhs.reference = refs[0];
+        return new Array(refs[1]);
+    }
+
     /**
      * Adds this array with the one passed as parameter.
      *

src/test/java/io/shapelets/khiva/ArrayTest.java

@@ -485,12 +485,23 @@ public void testGetType() throws Exception {
         }
     }
 
+    @Test
+    public void testJoin() throws Exception {
+        float[] data1 = {1f, 2f, 3f, 4f};
+        float[] data2 = {5f, 6f, 7f, 8f};
+        long[] dims = {4, 1, 1, 1};
+        try (Array a = new Array(data1, dims); Array b = new Array(data2, dims); Array c = a.join(1, b)) {
+            float[] result = c.getData();
+            float[] expected = {1f, 2f, 3f, 4f, 5f, 6f, 7f, 8f};
+            Assert.assertArrayEquals(result, expected, 1e-6f);
+        }
+    }
+
     @Test
     public void testAdd() throws Exception {
         float[] data = {1f, 2f, 3f, 4f};
         long[] dims = {4, 1, 1, 1};
         try (Array a = new Array(data, dims); Array b = new Array(data, dims); Array c = a.add(b)) {
-
             float[] result = c.getData();
             float[] expected = {2f, 4f, 6f, 8f};
             Assert.assertArrayEquals(result, expected, 1e-6f);