feat: move to java, use InferredExpression, and test java for RS_Squa…

…reRoot

common/src/main/java/org/apache/sedona/common/raster/MapAlgebra.java

@@ -332,6 +332,19 @@ public static double[] modulo(double[] band, double dividend) {
         return result;
     }
 
+    /**
+     * @param band band values
+     * @return an array, where each pixel has been applied square root operation.
+     */
+    public static double[] squareRoot(double[] band) {
+        double[] result = new double[band.length];
+        for (int i = 0; i < band.length; i++) {
+            result[i] = (double) Math.round(Math.sqrt(band[i]) * 100) / 100;
+        }
+
+        return result;
+    }
+
     /**
      * Throws an IllegalArgumentException if the lengths of the bands are not the same.
      * @param band1 length of band values

common/src/test/java/org/apache/sedona/common/raster/MapAlgebraTest.java

@@ -269,6 +269,14 @@ public void testModulo() {
         assertArrayEquals(expected, actual, 0.1d);
     }
 
+    @Test
+    public void testSquareRoot() {
+        double[] band = new double[] {8.0, 16.0, 24.0};
+        double[] actual = MapAlgebra.squareRoot(band);
+        double[] expected = new double[] {2.83, 4.0, 4.9};
+        assertArrayEquals(expected, actual, 0.01d);
+    }
+
     @Test
     public void testMapAlgebra() throws FactoryException {
         Random random = new Random();

spark/common/src/main/scala/org/apache/spark/sql/sedona_sql/expressions/raster/MapAlgebra.scala

@@ -391,32 +391,7 @@ case class RS_Modulo(inputExpressions: Seq[Expression]) extends InferredExpressi
 }
 
 // Square root of values in a band
-case class RS_SquareRoot(inputExpressions: Seq[Expression])
-  extends Expression with CodegenFallback with UserDataGeneratator {
-  assert(inputExpressions.length == 1)
-
-  override def nullable: Boolean = false
-
-  override def eval(inputRow: InternalRow): Any = {
-    val band = inputExpressions(0).eval(inputRow).asInstanceOf[ArrayData].toDoubleArray()
-    new GenericArrayData(squareRoot(band))
-
-  }
-
-  private def squareRoot(band: Array[Double]):Array[Double] = {
-
-    val result = new Array[Double](band.length)
-    for(i<-0 until band.length) {
-      result(i) = (Math.sqrt(band(i))*100).round/100.toDouble
-    }
-    result
-
-  }
-
-  override def dataType: DataType = ArrayType(DoubleType)
-
-  override def children: Seq[Expression] = inputExpressions
-
+case class RS_SquareRoot(inputExpressions: Seq[Expression]) extends InferredExpression(MapAlgebra.squareRoot _) {
   protected def withNewChildrenInternal(newChildren: IndexedSeq[Expression]) = {
     copy(inputExpressions = newChildren)
   }