Merge pull request #264 from VisActor/fix/bin

fix: the lastbin range should be same as binStep, not threshold with …

Author: xile611

common/changes/@visactor/vdataset/fix-bin_2025-11-11-12-29.json

@@ -0,0 +1,10 @@
+{
+  "changes": [
+    {
+      "packageName": "@visactor/vdataset",
+      "comment": "Fix bin range is limits by max as threshold",
+      "type": "none"
+    }
+  ],
+  "packageName": "@visactor/vdataset"
+}

packages/vdataset/__tests__/bin.test.ts

@@ -17,6 +17,22 @@ describe('bin transform', () => {
     }
   });
 
+  test('bins in max value and threshold', () => {
+    const data = [1, 1, 1, 2, 5, 7, 8, 9, 10].map(v => ({ v }));
+    const bins = bin(data, { field: 'v', bins: 10 });
+    expect(bins.length).toBe(10);
+    expect(bins[9].x0).toBe(10);
+    expect(bins[9].x1).toBe(11);
+  });
+
+  test('bins in steps', () => {
+    const data = [1, 1, 1, 2, 5, 7, 8, 9, 10].map(v => ({ v }));
+    const bins = bin(data, { field: 'v', step: 2, bins: 10 });
+    expect(bins.length).toBe(6);
+    expect(bins[5].x0).toBe(10);
+    expect(bins[5].x1).toBe(12);
+  });
+
   test('step produces correct bin widths', () => {
     const data = [] as any[];
     for (let i = 0; i <= 20; i++) {
@@ -168,12 +184,12 @@ describe('bin transform', () => {
     const data = [{ v: 1.2 }, { v: 2.5 }, { v: 5.0 }, { v: 10.7 }];
     const out: any = bin(data, { field: 'v', bins: 3 });
     // expect thresholds to start at floor(min)=1 and use integer step ceil((max-start)/bins)=4
-    // thresholds -> [1, 5, 9, max]
+    // thresholds -> [1, 5, 9, 13]
     expect(out.length).toBe(3);
     expect(out[0].x0).toBeCloseTo(1, 12);
     expect(out[1].x0).toBeCloseTo(5, 12);
     expect(out[2].x0).toBeCloseTo(9, 12);
     // last x1 should be the actual max
-    expect(out[2].x1).toBeCloseTo(10.7, 12);
+    expect(out[2].x1).toBeCloseTo(13, 12);
   });
 });

packages/vdataset/src/transform/bin.ts

@@ -94,7 +94,7 @@ export const bin: Transform = (data: Array<object>, options?: IBinOptions) => {
     }
     thresholds = [startMin];
 
-    while (startMin < max) {
+    while (startMin <= max) {
       startMin += stepSize;
       thresholds.push(startMin);
     }
@@ -107,13 +107,13 @@ export const bin: Transform = (data: Array<object>, options?: IBinOptions) => {
       const stepSizeInt = Math.ceil((max - start) / bins);
       thresholds = new Array(bins + 1);
       for (let i = 0; i <= bins; i++) {
-        thresholds[i] = i === bins ? max : start + stepSizeInt * i;
+        thresholds[i] = start + stepSizeInt * i;
       }
     } else {
       const stepSize = (max - min) / bins;
       thresholds = new Array(bins + 1);
       for (let i = 0; i <= bins; i++) {
-        thresholds[i] = i === bins ? max : min + stepSize * i;
+        thresholds[i] = min + stepSize * i;
       }
     }
   }