Merge pull request #3329 from tynanford/total_array_formula

Add new formula function - arrayTotal

Author: tynanford

core/formula/doc/index.rst

@@ -126,6 +126,8 @@ element is defined as pow(array[x], exponent).
 **arraySum(VNumberArray array, VNumber offset)** - Returns a VNumberArray where each
 element is defined as array[x] + offset. To subtract, use negative offset.
 
+**arrayTotal(VNumberArray array)** - Returns the sum of all elements in the input array.
+
 **elementAt([VNumberArray | VStringArray] array , VNumber index)** - Returns a VNumber
 or VString at the specified index of the input array. If the index is invalid, a NaN or
 empty string is returned.

core/formula/src/main/java/org/csstudio/apputil/formula/array/ArrayTotalFunction.java

@@ -0,0 +1,49 @@
+package org.csstudio.apputil.formula.array;
+
+import org.epics.util.array.ListNumber;
+import org.epics.vtype.Alarm;
+import org.epics.vtype.Display;
+import org.epics.vtype.Time;
+import org.epics.vtype.VNumber;
+import org.epics.vtype.VNumberArray;
+import org.epics.vtype.VType;
+import org.phoebus.core.vtypes.VTypeHelper;
+
+import java.util.List;
+
+/**
+ * Sums all elements in an array and returns a single number.
+ */
+public class ArrayTotalFunction extends BaseArrayFunction {
+
+    @Override
+    public String getName() {
+        return "arrayTotal";
+    }
+
+    @Override
+    public String getDescription() {
+        return "Returns the sum of all elements in the array.";
+    }
+
+    @Override
+    public List<String> getArguments() {
+        return List.of("array");
+    }
+
+    @Override
+    public VType compute(VType... args) {
+        if (VTypeHelper.isNumericArray(args[0])) {
+            VNumberArray array = (VNumberArray) args[0];
+            ListNumber data = array.getData();
+            double sum = 0.0;
+            for (int i = 0; i < data.size(); i++) {
+                sum += data.getDouble(i);
+            }
+            return VNumber.of(sum, Alarm.none(), Time.now(), Display.none());
+        }
+        else {
+            return DEFAULT_NAN_DOUBLE;
+        }
+    }
+}

core/formula/src/main/resources/META-INF/services/org.csstudio.apputil.formula.spi.FormulaFunction

@@ -51,6 +51,7 @@ org.csstudio.apputil.formula.array.SubArrayFunction
 org.csstudio.apputil.formula.array.ElementAtNumberFunction
 org.csstudio.apputil.formula.array.HistogramOfFunction
 org.csstudio.apputil.formula.array.ArraySumFunction
+org.csstudio.apputil.formula.array.ArrayTotalFunction
 org.csstudio.apputil.formula.array.ArrayPowFunction
 org.csstudio.apputil.formula.array.ArrayMultiplicationFunction
 org.csstudio.apputil.formula.array.ArrayDivisionFunction

core/formula/src/test/java/org/csstudio/apputil/formula/array/ArrayTotalFunctionTest.java

@@ -0,0 +1,36 @@
+package org.csstudio.apputil.formula.array;
+
+import org.epics.util.array.ArrayDouble;
+import org.epics.vtype.Alarm;
+import org.epics.vtype.Display;
+import org.epics.vtype.Time;
+import org.epics.vtype.VNumberArray;
+import org.epics.vtype.VNumber;
+import org.epics.vtype.VType;
+import org.junit.jupiter.api.Test;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+public class ArrayTotalFunctionTest {
+
+    @Test
+    public void compute() {
+        ArrayTotalFunction totalArrayFunction = new ArrayTotalFunction();
+
+        assertEquals("arrayTotal",  totalArrayFunction.getName());
+        assertEquals("array", totalArrayFunction.getCategory());
+
+        VType array = VNumberArray.of(ArrayDouble.of(1.0, 2.0, 3.0), Alarm.none(), Time.now(), Display.none());
+
+        VNumber result = (VNumber)totalArrayFunction.compute(array);
+        assertEquals(6.0, result.getValue());
+
+        array = VNumberArray.of(ArrayDouble.of(1.0, 2.0, 3.0, Double.NaN), Alarm.none(), Time.now(), Display.none());
+        result = (VNumber)totalArrayFunction.compute(array);
+        assertEquals(Double.NaN, result.getValue());
+
+        array = VNumberArray.of(ArrayDouble.of(1.0, 2.0, 3.0, -6.0), Alarm.none(), Time.now(), Display.none());
+        result = (VNumber)totalArrayFunction.compute(array);
+        assertEquals(0.0, result.getValue());
+    }
+}