fix: xyObjectJoinX with y=0

mljs · Mar 10, 2021 · feaa0fe · feaa0fe
1 parent 1bc2fcf
commit feaa0fe
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Showing 4 changed files with 20 additions and 8 deletions.
diff --git a/src/xy/__tests__/xyJoinX.test.js b/src/xy/__tests__/xyJoinX.test.js
@@ -55,7 +55,7 @@ describe('xyJoinX', function () {
   it('join with 0', () => {
     let data = { x: [2, 3, 6], y: [0, 0, 0] };
     expect(xyJoinX(data)).toStrictEqual({
-      x: [2.5, 6],
+      x: [2, 6],
       y: [0, 0],
     });
   });

diff --git a/src/xy/xyJoinX.js b/src/xy/xyJoinX.js
@@ -25,13 +25,11 @@ export function xyJoinX(data = {}, options = {}) {
 
     if (difference <= currentDelta) {
       // we join
-      if (y[position] === 0 && y[i] === 0) {
-        x[position] = (x[position] + x[i]) / 2;
-      } else {
+      if (y[position] !== 0 || y[i] !== 0) {
         x[position] =
           (x[position] * y[position] + x[i] * y[i]) / (y[position] + y[i]);
+        y[position] += y[i];
       }
-      y[position] += y[i];
     } else {
       position++;
       x[position] = x[i];

diff --git a/src/xyObject/__tests__/xyObjectJoinX.test.js b/src/xyObject/__tests__/xyObjectJoinX.test.js
@@ -12,4 +12,16 @@ test('xyObjectJoinX', () => {
     { x: 0.5, y: 2 },
     { x: 3.5, y: 4 },
   ]);
+
+  let arrayXYzero = [
+    { x: 0, y: 0 },
+    { x: 1, y: 0 },
+    { x: 3, y: 0 },
+    { x: 4, y: 0 },
+  ];
+
+  expect(xyObjectJoinX(arrayXYzero, { xError: 1.1 })).toStrictEqual([
+    { x: 0, y: 0 },
+    { x: 3, y: 0 },
+  ]);
 });
diff --git a/src/xyObject/xyObjectJoinX.js b/src/xyObject/xyObjectJoinX.js
@@ -16,9 +16,11 @@ export function xyObjectJoinX(points, options = {}) {
   for (let point of points) {
     if (point.x - current.x <= xError) {
       // weighted sum
-      current.x =
-        (point.y / (current.y + point.y)) * (point.x - current.x) + current.x;
-      current.y += point.y;
+      if (current.y !== 0 || point.y !== 0) {
+        current.x =
+          (point.y / (current.y + point.y)) * (point.x - current.x) + current.x;
+        current.y += point.y;
+      }
     } else {
       current = {
         x: point.x,