collect unique and sum

index.html

@@ -71,6 +71,40 @@ var N = {
     }
 };
 </script>
+
+<script>
+
+var rows = [
+    ["a", 1],
+    ["b", 2],
+    ["a", 3],
+    ["b", 1],
+    ["a", 0],
+    ["b", 7],
+];
+Uniques = (inRows, inColumnIndex, inSumIndicies) =>
+{
+    let uniques = {};
+    inRows.forEach((inRow)=>
+    {
+        let value = inRow[inColumnIndex];
+        let match = uniques[value];
+        if(!match)
+        {
+            match = uniques[value] = {Sum:[...inRow], Rows:[]};
+        }
+        else
+        {
+            inSumIndicies.forEach(inIndex => match.Sum[inIndex] += inRow[inIndex]);
+        }
+        match.Rows.push(inRow);
+    });
+    return uniques;
+};
+console.log(Uniques(rows, 0, [1]));
+
+</script>
+
 <script>
 let tree1 = N.Create("root1",
     N.Create("branch1",