From c5aa3c662afc2e64f38616ba5d02a826d4b6a4a0 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=E6=9D=8E=E5=90=AF=E6=BA=90?= <liqiyuan@repeatlink.cn>
Date: Tue, 4 Aug 2026 11:28:42 +0800
Subject: [PATCH] fix(chart): refine axis number formatting

---
 README.md                                     |  2 +-
 package.json                                  |  2 +-
 src/components/core/layout.test.ts            | 15 ++-
 src/components/core/layout.ts                 | 30 ++----
 src/components/core/trackLayoutBuilder.ts     | 26 +-----
 src/components/core/types.ts                  |  3 -
 src/components/core/useWaveformLayout.ts      | 32 +------
 .../interaction/WaveformTooltip.test.ts       | 16 ++++
 .../rendering/WaveformTrackAxes.vue           | 30 +-----
 .../compactAndSharedHover.test.ts             | 14 +--
 .../dataAndHoverPerformance.test.ts           |  4 +-
 .../waveformChartCases/dataLifecycle.test.ts  |  8 +-
 .../frameGridAndFormatting.test.ts            | 51 +++++-----
 .../interactionAndAnnotationCreation.test.ts  |  2 +-
 .../layoutAndDomains.test.ts                  | 30 +++---
 .../multiAxisAndPagination.test.ts            | 16 ++--
 .../presentationAndAxes.test.ts               | 10 +-
 .../viewportConstraintsAndReset.test.ts       | 16 ++--
 .../waveformChartCases/wheelZoomOut.test.ts   |  6 +-
 src/utils/formatters.test.ts                  | 73 ++++++++-------
 src/utils/formatters.ts                       | 92 +++++++++----------
 src/utils/index.ts                            |  1 -
 22 files changed, 217 insertions(+), 262 deletions(-)

diff --git a/README.md b/README.md
index 9619ecb..b1fea85 100644
--- a/README.md
+++ b/README.md
@@ -603,7 +603,7 @@ async function importAnnotationFile(file: File) {
 字段无效时会抛出 `TypeError`，不会返回部分结果。导入包含未知 `seriesId` 的标注是允许的，
 对应曲线加载后会恢复显示。文件选择、错误提示和下载由业务层实现。
 
-X、Y 轴会根据各自完整显示域选择格式：最大绝对值在 `[0.01, 100)` 时显示两位普通小数；大于等于 `100`，或大于 `0` 且小于 `0.01` 时，刻度显示两位缩放值，并在轴末端单独显示共享倍率 `E±NN`。X 轴先按 `timeUnit` 转换为秒或毫秒再判断范围，多 Y 轴则分别计算倍率。tooltip 使用最多 4 位小数的本地化普通数字；标注编辑器的 X 坐标跟随 `timeUnit` 并固定 3 位小数，Y 坐标显示完整普通十进制。所有格式化都只发生在展示层，内部坐标值保持原始精度。
+X 轴刻度和左右端点先按 `timeUnit` 转换为秒或毫秒，再四舍五入为不带分组符的普通整数，不使用科学计数法。Y 轴会根据完整显示域选择格式：最大绝对值在 `[0.01, 100)` 时显示两位普通小数；大于等于 `100`，或大于 `0` 且小于 `0.01` 时，刻度显示两位缩放值，并在轴末端单独显示共享倍率 `E±NN`，多 Y 轴分别计算倍率。tooltip 使用最多 4 位小数的本地化普通数字并省略无意义尾零；标注编辑器的 X 坐标跟随 `timeUnit` 并固定 3 位小数，Y 坐标显示完整普通十进制。所有格式化都只发生在展示层，内部坐标值保持原始精度。
 标注框默认布局在采样点正上方，只做绘图区边界裁剪；文本框通过连接箭头指向标注位置，多个标注重叠时可通过拖动手动避让。
 
 ## 事件
diff --git a/package.json b/package.json
index 1731e1f..a57c415 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "waveform-analysis",
-  "version": "0.1.27",
+  "version": "0.1.28",
   "main": "./dist/index.cjs",
   "module": "./dist/index.js",
   "types": "./dist/types/index.d.ts",
diff --git a/src/components/core/layout.test.ts b/src/components/core/layout.test.ts
index 2462437..32ec402 100644
--- a/src/components/core/layout.test.ts
+++ b/src/components/core/layout.test.ts
@@ -192,7 +192,7 @@ describe('multi-value Y-axis grouping', () => {
     ])
   })
 
-  it('places left and right scientific exponents eight pixels outside their tick labels', () => {
+  it('reserves label clearance for exponent-prefixed ticks on both axis sides', () => {
     const layout = buildTrackLayouts({
       cells: [
         {
@@ -206,7 +206,7 @@ describe('multi-value Y-axis grouping', () => {
           plotHeight: 300,
           cellHeight: 330,
           xAxisBand: 30,
-          series: track([series('left', 0, 254), series('right', 0, 254)]),
+          series: track([series('left', 1000, 3000), series('right', 1000, 3000)]),
         },
       ],
       grid: { rowCount: 1, columnCount: 1, showPagination: false, trackLines: {} },
@@ -222,14 +222,13 @@ describe('multi-value Y-axis grouping', () => {
     })[0]
 
     expect(
-      layout?.yAxes.map(({ side, x, exponentX, exponentLabel }) => ({
+      layout?.yAxes.map(({ side, x, labelX }) => ({
         side,
-        offset: Math.abs(exponentX - x),
-        exponentLabel,
+        labelOffset: Math.abs(labelX - x),
       })),
     ).toEqual([
-      { side: 'left', offset: 43, exponentLabel: 'E+02' },
-      { side: 'right', offset: 43, exponentLabel: 'E+02' },
+      { side: 'left', labelOffset: 67 },
+      { side: 'right', labelOffset: 67 },
     ])
   })
 
@@ -237,7 +236,7 @@ describe('multi-value Y-axis grouping', () => {
     const [group] = buildYAxisSeriesGroups(track([series('long', -1e120, 1e120)]), 'multi-axis')
 
     expect(group).toBeDefined()
-    expect(measureYAxisGroupClearance(group!)).toBe(119)
+    expect(measureYAxisGroupClearance(group!)).toBe(90)
   })
 })
 
diff --git a/src/components/core/layout.ts b/src/components/core/layout.ts
index e0b85a9..60d53dd 100644
--- a/src/components/core/layout.ts
+++ b/src/components/core/layout.ts
@@ -1,9 +1,9 @@
 import { scaleLinear } from 'd3'
 
 import type { WaveformOverlayMode } from '../../types'
-import { formatScientificAxisExponent, formatScientificAxisLabel, paddedDomain } from '../../utils'
+import { formatScientificAxisLabel, paddedDomain } from '../../utils'
 import type { DisplaySeries, DisplayTrack, TrackLayout } from './types'
-import { MAX_MULTI_Y_AXIS_COUNT, Y_AXIS_EXPONENT_GAP } from './constants'
+import { MAX_MULTI_Y_AXIS_COUNT } from './constants'
 import {
   mergeYDomains,
   resolveSeriesFixedYDomain,
@@ -12,7 +12,7 @@ import {
 } from './yDomain'
 
 // 导出常量供外部使用
-export { MAX_MULTI_Y_AXIS_COUNT, Y_AXIS_EXPONENT_GAP } from './constants'
+export { MAX_MULTI_Y_AXIS_COUNT } from './constants'
 
 const Y_AXIS_CHARACTER_WIDTH = 7
 const Y_AXIS_TICK_PADDING = 7
@@ -102,36 +102,27 @@ export function resolveYAxisSeriesGroups(
 export function axisTextMetrics(
   domain: [number, number],
   nice = true,
-): {
-  exponentLabel: string | null
-  exponentWidth: number
-  tickTextWidth: number
-} {
+  tickValues?: number[],
+): { tickTextWidth: number } {
   const scale = scaleLinear(domain, [1, 0])
   if (nice) scale.nice()
   const [axisMin, axisMax] = scale.domain()
-  const values = scale.ticks(10)
+  const values = tickValues ?? Array.from(new Set([axisMin, ...scale.ticks(10), axisMax]))
+  const topTickValue = Math.max(...values)
   const maximumTickCharacters = Math.max(
     1,
-    ...values.map((value) => formatScientificAxisLabel(value, { axisMin, axisMax }).length),
+    ...values.map(
+      (value) => formatScientificAxisLabel(value, { axisMin, axisMax, topTickValue }).length,
+    ),
   )
-  const exponentLabel = formatScientificAxisExponent(axisMin, axisMax)
   return {
-    exponentLabel,
-    exponentWidth: exponentLabel ? exponentLabel.length * Y_AXIS_CHARACTER_WIDTH : 0,
     tickTextWidth: maximumTickCharacters * Y_AXIS_CHARACTER_WIDTH,
   }
 }
 
-function axisExponentClearance(domain: [number, number], nice: boolean): number {
-  const { exponentLabel, exponentWidth } = axisTextMetrics(domain, nice)
-  return exponentLabel ? exponentWidth + Y_AXIS_EXPONENT_GAP : 0
-}
-
 export function measureYAxisGroupClearance(group: YAxisSeriesGroup): number {
   return (
     axisTextMetrics(group.domain, !group.fixed).tickTextWidth +
-    axisExponentClearance(group.domain, !group.fixed) +
     Y_AXIS_TICK_PADDING +
     Y_AXIS_LABEL_GAP +
     Y_AXIS_LABEL_BAND_WIDTH +
@@ -142,7 +133,6 @@ export function measureYAxisGroupClearance(group: YAxisSeriesGroup): number {
 function measureYAxisGroupTickClearance(group: YAxisSeriesGroup): number {
   return (
     axisTextMetrics(group.domain, !group.fixed).tickTextWidth +
-    axisExponentClearance(group.domain, !group.fixed) +
     Y_AXIS_TICK_PADDING +
     Y_AXIS_OUTER_PADDING
   )
diff --git a/src/components/core/trackLayoutBuilder.ts b/src/components/core/trackLayoutBuilder.ts
index 6183576..cd3ba72 100644
--- a/src/components/core/trackLayoutBuilder.ts
+++ b/src/components/core/trackLayoutBuilder.ts
@@ -13,7 +13,7 @@ import {
   type ResolvedWaveformRenderingOptions,
 } from '../../core/rendering'
 import type { WaveformDisplayMode, WaveformOverlayMode, WaveformPoint } from '../../types'
-import { buildMinorTicks, formatAxisTimeExponent, formatEndpointTime } from '../../utils'
+import { buildMinorTicks, formatEndpointTime } from '../../utils'
 import {
   getBottomRowCellIndexes,
   type GridCellGeometry,
@@ -21,7 +21,6 @@ import {
 } from './grid'
 import { axisTextMetrics, resolveYAxisSeriesGroups } from './layout'
 import type { DisplaySeries, DisplayTrack, TrackLayout, WaveformYAxisLayout } from './types'
-import { Y_AXIS_EXPONENT_GAP } from './constants'
 import {
   Y_AXIS_LABEL_BAND_WIDTH,
   Y_AXIS_LABEL_GAP,
@@ -118,31 +117,16 @@ export function buildTrackLayouts(options: BuildTrackLayoutsOptions): TrackLayou
       const tickValues = Array.from(
         new Set([axisStart, ...visibleMajorTicks, ...(showAxisEnd ? [axisEnd] : [])]),
       )
-      const { exponentLabel, exponentWidth, tickTextWidth } = axisTextMetrics(
-        group.domain,
-        !group.fixed,
-      )
-      const exponentClearance = exponentLabel ? exponentWidth + Y_AXIS_EXPONENT_GAP : 0
+      const { tickTextWidth } = axisTextMetrics(group.domain, !group.fixed, tickValues)
       const clearance =
         tickTextWidth +
         Y_AXIS_TICK_PADDING +
-        exponentClearance +
         Y_AXIS_LABEL_GAP +
         Y_AXIS_LABEL_BAND_WIDTH +
         Y_AXIS_OUTER_PADDING
       const x = group.side === 'left' ? -sideOffsets.left : cell.width + sideOffsets.right
-      const exponentX =
-        x +
-        (group.side === 'left'
-          ? -(Y_AXIS_TICK_PADDING + tickTextWidth + Y_AXIS_EXPONENT_GAP)
-          : Y_AXIS_TICK_PADDING + tickTextWidth + Y_AXIS_EXPONENT_GAP)
       const labelDistance =
-        tickTextWidth +
-        Y_AXIS_TICK_PADDING +
-        exponentClearance +
-        exponentWidth +
-        Y_AXIS_LABEL_GAP +
-        Y_AXIS_LABEL_BAND_WIDTH / 2
+        tickTextWidth + Y_AXIS_TICK_PADDING + Y_AXIS_LABEL_GAP + Y_AXIS_LABEL_BAND_WIDTH / 2
       const labelX = x + (group.side === 'left' ? -labelDistance : labelDistance)
       sideOffsets[group.side] += clearance
       return {
@@ -150,8 +134,6 @@ export function buildTrackLayouts(options: BuildTrackLayoutsOptions): TrackLayou
         side: group.side,
         x,
         labelX,
-        exponentX,
-        exponentLabel,
         scale,
         majorTicks,
         minorTicks: buildMinorTicks(majorTicks),
@@ -168,7 +150,6 @@ export function buildTrackLayouts(options: BuildTrackLayoutsOptions): TrackLayou
       start: formatEndpointTime(domain[0], domain, options.timeUnit),
       end: formatEndpointTime(domain[1], domain, options.timeUnit),
     }
-    const xAxisExponent = formatAxisTimeExponent(domain, options.timeUnit)
     const leftClearance = endpointLabels.start.length * 7 + 10
     const rightClearance = endpointLabels.end.length * 7 + 10
     const xAxisTickValues = xMajorTicks.filter((tick) => {
@@ -235,7 +216,6 @@ export function buildTrackLayouts(options: BuildTrackLayoutsOptions): TrackLayou
       yAxisTickValues,
       xAxisTickValues,
       endpointLabels,
-      xAxisExponent,
       path: seriesPaths[0]?.path ?? null,
       seriesPaths,
       gridLines: options.grid.trackLines[displayTrack.id] ?? {
diff --git a/src/components/core/types.ts b/src/components/core/types.ts
index ed375bd..e962798 100644
--- a/src/components/core/types.ts
+++ b/src/components/core/types.ts
@@ -51,8 +51,6 @@ export interface WaveformYAxisLayout {
   side: 'left' | 'right'
   x: number
   labelX: number
-  exponentX: number
-  exponentLabel: string | null
   scale: ScaleLinear<number, number>
   majorTicks: number[]
   minorTicks: number[]
@@ -109,7 +107,6 @@ export interface TrackLayout {
   yAxisTickValues: number[]
   xAxisTickValues: number[]
   endpointLabels: { start: string; end: string }
-  xAxisExponent: string | null
   path: string | null
   seriesPaths: TrackSeriesPath[]
   showXAxis: boolean
diff --git a/src/components/core/useWaveformLayout.ts b/src/components/core/useWaveformLayout.ts
index 090ca93..3c3e45c 100644
--- a/src/components/core/useWaveformLayout.ts
+++ b/src/components/core/useWaveformLayout.ts
@@ -2,7 +2,7 @@ import { scaleLinear, type ZoomTransform } from 'd3'
 import { computed, type ComputedRef, type Ref, type ShallowRef } from 'vue'
 
 import { resolveWaveformRenderingOptions } from '../../core'
-import { formatScientificAxisExponent, formatScientificAxisLabel, paddedDomain } from '../../utils'
+import { paddedDomain } from '../../utils'
 import {
   layoutAnnotations,
   type AnnotationSeriesInfo,
@@ -28,9 +28,9 @@ import {
 } from './grid'
 import {
   buildTrackLayouts,
+  axisTextMetrics,
   measureTrackYAxisClearance,
   resolveYAxisSeriesGroups,
-  Y_AXIS_EXPONENT_GAP,
 } from './layout'
 import type { DisplaySeries, DisplayTrack, TrackLayout } from './types'
 import type { PreparedWaveformSeries } from './useWaveformData'
@@ -112,40 +112,18 @@ export function useWaveformLayout(context: LayoutContext) {
       .flatMap((track) =>
         resolveYAxisSeriesGroups(track, props.overlayMode, props.yDomain, props.yDomains),
       )
-      .map((group) => {
-        const scale = scaleLinear(group.domain, [1, 0])
-        if (!group.fixed) scale.nice()
-        const [axisMin, axisMax] = scale.domain()
-        return {
-          exponentLabel: formatScientificAxisExponent(axisMin, axisMax),
-          tickLabels: scale
-            .ticks(10)
-            .map((value) => formatScientificAxisLabel(value, { axisMin, axisMax })),
-        }
-      })
-    const maximumCharacters = Math.max(
-      1,
-      ...axisText.flatMap(({ tickLabels }) => tickLabels).map((label) => label.length),
-    )
-    const tickTextWidth = maximumCharacters * Y_AXIS_CHARACTER_WIDTH
-    const maximumExponentWidth = Math.max(
-      0,
-      ...axisText.map(({ exponentLabel }) => (exponentLabel?.length ?? 0) * Y_AXIS_CHARACTER_WIDTH),
-    )
-    const exponentClearance = maximumExponentWidth ? maximumExponentWidth + Y_AXIS_EXPONENT_GAP : 0
-    const tickClearance =
-      tickTextWidth + Y_AXIS_TICK_PADDING + exponentClearance + Y_AXIS_OUTER_PADDING
+      .map((group) => axisTextMetrics(group.domain, !group.fixed).tickTextWidth)
+    const tickTextWidth = Math.max(Y_AXIS_CHARACTER_WIDTH, ...axisText)
+    const tickClearance = tickTextWidth + Y_AXIS_TICK_PADDING + Y_AXIS_OUTER_PADDING
     const labelCenterX = -(
       Y_AXIS_TICK_PADDING +
       tickTextWidth +
-      exponentClearance +
       Y_AXIS_LABEL_GAP +
       Y_AXIS_LABEL_BAND_WIDTH / 2
     )
     const fullClearance =
       tickTextWidth +
       Y_AXIS_TICK_PADDING +
-      exponentClearance +
       Y_AXIS_LABEL_GAP +
       Y_AXIS_LABEL_BAND_WIDTH +
       Y_AXIS_OUTER_PADDING
diff --git a/src/components/interaction/WaveformTooltip.test.ts b/src/components/interaction/WaveformTooltip.test.ts
index 07e81d5..38489bf 100644
--- a/src/components/interaction/WaveformTooltip.test.ts
+++ b/src/components/interaction/WaveformTooltip.test.ts
@@ -91,6 +91,22 @@ describe('WaveformTooltip', () => {
     expect(wrapper.get('.waveform-tooltip__value').text()).toBe('-1,405.4932 A')
   })
 
+  it('formats tooltip time with at most four decimal places', () => {
+    const wrapper = mount(WaveformTooltip, {
+      props: {
+        visible: true,
+        position: { x: 10, y: 10 },
+        timeUnit: 's',
+        hoveredPoint: { x: 1.234567, y: 12 },
+        seriesPoints: [],
+        containerWidth: 400,
+        containerHeight: 300,
+      },
+    })
+
+    expect(wrapper.get('.waveform-tooltip__time').text()).toBe('s: 1.2346')
+  })
+
   it('omits the error label when both resolved errors are zero', () => {
     const point = { x: 1, y: 12 }
     const wrapper = mount(WaveformTooltip, {
diff --git a/src/components/rendering/WaveformTrackAxes.vue b/src/components/rendering/WaveformTrackAxes.vue
index bd88574..cf75adc 100644
--- a/src/components/rendering/WaveformTrackAxes.vue
+++ b/src/components/rendering/WaveformTrackAxes.vue
@@ -43,8 +43,11 @@ function renderAxes() {
     const element = yAxisElements.value[index]
     if (!element) return
     const [axisMin, axisMax] = axis.scale.domain()
+    const topTickValue = Math.max(...axis.tickValues)
     const yAxis = (axis.side === 'left' ? axisLeft(axis.scale) : axisRight(axis.scale))
-      .tickFormat((value) => formatScientificAxisLabel(Number(value), { axisMin, axisMax }))
+      .tickFormat((value) =>
+        formatScientificAxisLabel(Number(value), { axisMin, axisMax, topTickValue }),
+      )
       .tickSize(-4)
       .tickPadding(7)
       .tickSizeOuter(0)
@@ -136,17 +139,6 @@ watch(
       {{ track.endpointLabels.end }}
     </text>
   </g>
-  <text
-    v-if="track.showXAxis && track.xAxisExponent"
-    class="waveform-track__axis-exponent waveform-track__axis-exponent--x waveform-chart__axis-exponent waveform-chart__axis-exponent--x"
-    :x="track.width ?? innerWidth"
-    :y="track.height + 27"
-    text-anchor="end"
-    aria-hidden="true"
-  >
-    {{ track.xAxisExponent }}
-  </text>
-
   <g
     v-for="axis in track.isEmpty ? [] : track.yAxes"
     :key="`y-axis-${track.index}-${axis.index}`"
@@ -160,20 +152,6 @@ watch(
     :data-y-axis-side="axis.side"
     :transform="`translate(${axis.x}, 0)`"
   />
-  <text
-    v-for="axis in track.isEmpty ? [] : track.yAxes.filter((item) => item.exponentLabel)"
-    :key="`y-axis-exponent-${track.index}-${axis.index}`"
-    class="waveform-track__axis-exponent waveform-track__axis-exponent--y waveform-chart__axis-exponent waveform-chart__axis-exponent--y"
-    :data-y-axis-index="axis.index"
-    :x="axis.exponentX"
-    y="0"
-    dy="0.32em"
-    :text-anchor="axis.side === 'left' ? 'end' : 'start'"
-    aria-hidden="true"
-  >
-    {{ axis.exponentLabel }}
-  </text>
-
   <g
     v-if="
       !cleanView &&
diff --git a/src/components/waveformChartCases/compactAndSharedHover.test.ts b/src/components/waveformChartCases/compactAndSharedHover.test.ts
index 732904c..e664db4 100644
--- a/src/components/waveformChartCases/compactAndSharedHover.test.ts
+++ b/src/components/waveformChartCases/compactAndSharedHover.test.ts
@@ -72,7 +72,7 @@ describe('WaveformChart', () => {
     expect(endTicks[3]).toHaveLength(0)
   })
 
-  it('keeps one separate shared exponent for every compact Y axis', async () => {
+  it('prefixes one shared exponent to the largest visible tick on every compact Y axis', async () => {
     const wrapper = await mountSizedChart(
       {
         kind: 'series',
@@ -83,7 +83,7 @@ describe('WaveformChart', () => {
               kind: 'points',
               points: [
                 { x: 0, y: 0 },
-                { x: 1, y: 254 },
+                { x: 1, y: 2540 },
               ],
             },
           },
@@ -103,14 +103,14 @@ describe('WaveformChart', () => {
     )
 
     const axes = wrapper.findAll('.waveform-chart__axis--y')
-    const exponents = wrapper.findAll('.waveform-chart__axis-exponent--y')
     expect(axes).toHaveLength(2)
-    expect(exponents.map((label) => label.text())).toEqual(['E+02', 'E-04'])
-    axes.forEach((axis) => {
+    axes.forEach((axis, index) => {
       const labels = axis.findAll('.tick text').map((tick) => tick.text())
-      expect(labels.every((label) => !label.startsWith('E'))).toBe(true)
-      expect(labels.every((label) => /^-?\d+\.\d{2}$/.test(label))).toBe(true)
+      const exponentLabels = labels.filter((label) => label.startsWith('E'))
+      expect(exponentLabels).toHaveLength(1)
+      expect(exponentLabels[0]).toMatch(index === 0 ? /^E\+03 / : /^E-04 /)
     })
+    expect(wrapper.find('.waveform-chart__axis-exponent--y').exists()).toBe(false)
   })
 
   it('prefers a trimmed series name and falls back to yLabel for unnamed data', async () => {
diff --git a/src/components/waveformChartCases/dataAndHoverPerformance.test.ts b/src/components/waveformChartCases/dataAndHoverPerformance.test.ts
index 5ebea32..a9767c6 100644
--- a/src/components/waveformChartCases/dataAndHoverPerformance.test.ts
+++ b/src/components/waveformChartCases/dataAndHoverPerformance.test.ts
@@ -178,7 +178,7 @@ describe('WaveformChart', () => {
     await flushPromises()
     expect(wrapper.emitted('point-hover')?.at(-1)).toEqual([{ x: 1, y: 5 }])
     expect(wrapper.find('.waveform-chart__tooltip').exists()).toBe(true)
-    expect(wrapper.get('.waveform-chart__tooltip').text()).toContain('ms: 1,000.0000')
+    expect(wrapper.get('.waveform-chart__tooltip-time').text()).toBe('ms: 1,000')
     const crosshairLines = wrapper.findAll('.waveform-chart__crosshair line')
     expect(crosshairLines).toHaveLength(1)
     expect(crosshairLines[0].attributes('x1')).toBe(crosshairLines[0].attributes('x2'))
@@ -303,7 +303,7 @@ describe('WaveformChart', () => {
     flushAnimationFrames()
     await flushPromises()
 
-    expect(wrapper.get('.waveform-chart__tooltip').text()).toContain('ms: 1,000.0000')
+    expect(wrapper.get('.waveform-chart__tooltip-time').text()).toBe('ms: 1,000')
     expect(wrapper.findAll('.waveform-chart__crosshair line')).toHaveLength(1)
     expect(wrapper.get('.waveform-chart__line').element).toBe(pathBeforeHover)
     expect(chartUpdate).not.toHaveBeenCalled()
diff --git a/src/components/waveformChartCases/dataLifecycle.test.ts b/src/components/waveformChartCases/dataLifecycle.test.ts
index c6da32d..1ba3215 100644
--- a/src/components/waveformChartCases/dataLifecycle.test.ts
+++ b/src/components/waveformChartCases/dataLifecycle.test.ts
@@ -62,15 +62,15 @@ describe('WaveformChart', () => {
       ],
     }
     const wrapper = await mountSizedChart(firstData)
-    expect(wrapper.get('.waveform-chart__axis-endpoint--end').text()).toBe('1.00')
+    expect(wrapper.get('.waveform-chart__axis-endpoint--end').text()).toBe('1000')
 
     firstData.points.push({ x: 2, y: 2 })
     await flushPromises()
-    expect(wrapper.get('.waveform-chart__axis-endpoint--end').text()).toBe('1.00')
+    expect(wrapper.get('.waveform-chart__axis-endpoint--end').text()).toBe('1000')
 
     await wrapper.setProps({ data: { ...firstData, points: [...firstData.points] } })
     await flushPromises()
-    expect(wrapper.get('.waveform-chart__axis-endpoint--end').text()).toBe('2.00')
+    expect(wrapper.get('.waveform-chart__axis-endpoint--end').text()).toBe('2000')
   })
 
   it('keeps controlled annotations when replacing the loaded data window', async () => {
@@ -170,7 +170,7 @@ describe('WaveformChart', () => {
     expect(wrapper.findAll('.waveform-chart__track-label')).toHaveLength(0)
     expect(
       wrapper.findAll('.waveform-chart__axis-endpoint--end').map((item) => item.text()),
-    ).toEqual(['1.00', '2.00'])
+    ).toEqual(['1000', '2000'])
   })
 
   it('keeps the zero Y-axis label on upper compact tracks', async () => {
diff --git a/src/components/waveformChartCases/frameGridAndFormatting.test.ts b/src/components/waveformChartCases/frameGridAndFormatting.test.ts
index 2342b96..ddfaa0f 100644
--- a/src/components/waveformChartCases/frameGridAndFormatting.test.ts
+++ b/src/components/waveformChartCases/frameGridAndFormatting.test.ts
@@ -162,35 +162,42 @@ describe('WaveformChart', () => {
     expect(wrapper.get('.waveform-chart__axis-endpoint--end').attributes('x')).toBe(
       String(trackWidth),
     )
-    expect(wrapper.get('.waveform-chart__axis-endpoint--end').text()).toBe('4.99')
-    expect(wrapper.get('.waveform-chart__axis-exponent--x').text()).toBe('E+03')
+    expect(wrapper.get('.waveform-chart__axis-endpoint--end').text()).toBe('4990')
+    expect(wrapper.find('.waveform-chart__axis-exponent--x').exists()).toBe(false)
   })
 
   it('uses one shared scientific exponent only for large and tiny Y-axis domains', async () => {
     const cases = [
-      { values: [0, 50], exponent: null },
-      { values: [0, 254], exponent: 'E+02' },
-      { values: [0, 0.0002], exponent: 'E-04' },
+      { values: [0, 50], yDomain: [0, 50] as [number, number], exponent: null },
+      { values: [1000, 3000], yDomain: [1000, 3000] as [number, number], exponent: 'E+03' },
+      {
+        values: [0.0001, 0.0003],
+        yDomain: [0.0001, 0.0003] as [number, number],
+        exponent: 'E-04',
+      },
     ]
 
-    for (const { values, exponent } of cases) {
-      const wrapper = await mountSizedChart({
-        kind: 'points',
+    for (const { values, yDomain, exponent } of cases) {
+      const data = {
+        kind: 'points' as const,
         points: values.map((y, x) => ({ x, y })),
-      })
+      }
+      const originalValues = data.points.map((point) => point.y)
+      const wrapper = await mountSizedChart(data, { yDomain })
       const labels = wrapper
         .get('.waveform-chart__axis--y')
         .findAll('.tick text')
         .map((tick) => tick.text())
-      const exponentLabel = wrapper.find('.waveform-chart__axis-exponent--y')
+      const exponentLabels = labels.filter((label) => label.startsWith('E'))
 
       if (exponent === null) {
-        expect(exponentLabel.exists()).toBe(false)
+        expect(exponentLabels).toHaveLength(0)
       } else {
-        expect(exponentLabel.text()).toBe(exponent)
-        expect(labels.every((label) => !label.startsWith('E'))).toBe(true)
-        expect(labels.every((label) => /^-?\d+\.\d{2}$/.test(label))).toBe(true)
+        expect(exponentLabels).toHaveLength(1)
+        expect(exponentLabels[0]).toMatch(new RegExp(`^${exponent.replace('+', '\\+')} `))
       }
+      expect(wrapper.find('.waveform-chart__axis-exponent--y').exists()).toBe(false)
+      expect(data.points.map((point) => point.y)).toEqual(originalValues)
 
       wrapper.unmount()
     }
@@ -212,13 +219,13 @@ describe('WaveformChart', () => {
 
     expect(millisecondsChart.text()).toContain('时间（ms）')
     expect(millisecondTicks.length).toBeGreaterThan(0)
-    expect(millisecondsChart.get('.waveform-chart__axis-endpoint--end').text()).toBe('1.00')
-    expect(millisecondsChart.get('.waveform-chart__axis-exponent--x').text()).toBe('E+03')
+    expect(millisecondsChart.get('.waveform-chart__axis-endpoint--end').text()).toBe('1000')
+    expect(millisecondsChart.find('.waveform-chart__axis-exponent--x').exists()).toBe(false)
     expect(millisecondsChart.find('.waveform-chart__watermark').exists()).toBe(false)
 
     const secondsChart = await mountSizedChart(data, { timeUnit: 's', xLabel: 'Elapsed time' })
     expect(secondsChart.text()).toContain('Elapsed time')
-    expect(secondsChart.get('.waveform-chart__axis-endpoint--end').text()).toBe('1.00')
+    expect(secondsChart.get('.waveform-chart__axis-endpoint--end').text()).toBe('1')
     expect(secondsChart.find('.waveform-chart__axis-exponent--x').exists()).toBe(false)
   })
 
@@ -237,15 +244,15 @@ describe('WaveformChart', () => {
 
     expect(start.attributes('x')).toBe('0')
     expect(start.attributes('text-anchor')).toBe('start')
-    expect(start.text()).toBe('0.00')
+    expect(start.text()).toBe('0')
     expect(end.attributes('x')).toBe(
       wrapper.get('.waveform-chart__track').attributes('data-track-width'),
     )
     expect(end.attributes('text-anchor')).toBe('end')
-    expect(end.text()).toBe('2.00')
+    expect(end.text()).toBe('1999')
     expect(middleTickLabels.length).toBeGreaterThan(0)
-    expect(middleTickLabels).not.toContain('0.00')
-    expect(wrapper.get('.waveform-chart__axis-exponent--x').text()).toBe('E+03')
+    expect(middleTickLabels).not.toContain('0')
+    expect(wrapper.find('.waveform-chart__axis-exponent--x').exists()).toBe(false)
     expect(wrapper.findAll('.waveform-chart__grid--major line').length).toBeGreaterThan(
       middleTickLabels.length,
     )
@@ -300,6 +307,6 @@ describe('WaveformChart', () => {
     )
     expect(wrapper.get('.waveform-chart__axis-endpoint--start').text()).not.toBe(initialStart)
     expect(wrapper.get('.waveform-chart__axis-endpoint--end').text()).not.toBe(initialEnd)
-    expect(wrapper.get('.waveform-chart__axis-endpoint--start').text()).toContain('.')
+    expect(wrapper.get('.waveform-chart__axis-endpoint--start').text()).toMatch(/^-?\d+$/)
   })
 })
diff --git a/src/components/waveformChartCases/interactionAndAnnotationCreation.test.ts b/src/components/waveformChartCases/interactionAndAnnotationCreation.test.ts
index 63e65ca..0402558 100644
--- a/src/components/waveformChartCases/interactionAndAnnotationCreation.test.ts
+++ b/src/components/waveformChartCases/interactionAndAnnotationCreation.test.ts
@@ -59,7 +59,7 @@ describe('WaveformChart', () => {
     await flushPromises()
 
     expect(wrapper.findAll('.waveform-chart__axis--x')).toHaveLength(1)
-    expect(wrapper.get('.waveform-chart__axis-endpoint--end').text()).toBe('2.00')
+    expect(wrapper.get('.waveform-chart__axis-endpoint--end').text()).toBe('2000')
   })
 
   it('updates rendering props and disables zoom interaction', async () => {
diff --git a/src/components/waveformChartCases/layoutAndDomains.test.ts b/src/components/waveformChartCases/layoutAndDomains.test.ts
index 9044c90..da42b71 100644
--- a/src/components/waveformChartCases/layoutAndDomains.test.ts
+++ b/src/components/waveformChartCases/layoutAndDomains.test.ts
@@ -33,10 +33,10 @@ describe('WaveformChart', () => {
       tracks[0].get('.waveform-chart__y-axis-label-bg').attributes('x'),
     )
 
-    expect(labelX).toBe(-103)
+    expect(labelX).toBe(-74)
     expect(labelBackgroundX).toBe(labelX - 12)
-    expect(Number(wrapper.attributes('data-chart-left-margin'))).toBe(119)
-    expect(secondLeft - firstWidth).toBeGreaterThanOrEqual(119)
+    expect(Number(wrapper.attributes('data-chart-left-margin'))).toBe(90)
+    expect(secondLeft - firstWidth).toBeGreaterThanOrEqual(90)
   })
 
   it('keeps a tick-only gutter when channel labels are empty', async () => {
@@ -62,8 +62,8 @@ describe('WaveformChart', () => {
     const secondLeft = Number(tracks[1].attributes('data-track-left'))
 
     expect(wrapper.findAll('.waveform-chart__y-axis-label')).toHaveLength(0)
-    expect(Number(wrapper.attributes('data-chart-left-margin'))).toBe(89)
-    expect(secondLeft - firstWidth).toBeGreaterThanOrEqual(89)
+    expect(Number(wrapper.attributes('data-chart-left-margin'))).toBe(64)
+    expect(secondLeft - firstWidth).toBeGreaterThanOrEqual(60)
   })
 
   it('keeps the Y-axis label gutter stable while paging between value ranges', async () => {
@@ -122,7 +122,7 @@ describe('WaveformChart', () => {
     const tracks = wrapper.findAll('.waveform-chart__track')
     const firstWidth = Number(tracks[0].attributes('data-track-width'))
     const secondLeft = Number(tracks[1].attributes('data-track-left'))
-    expect(secondLeft - firstWidth).toBeGreaterThanOrEqual(39)
+    expect(secondLeft - firstWidth).toBeGreaterThanOrEqual(32)
   })
 
   it('uses one shared overlay and bottom-row x axes for separated and compact grids', async () => {
@@ -262,10 +262,10 @@ describe('WaveformChart', () => {
     )
 
     const tracks = wrapper.findAll('.waveform-chart__track')
-    expect(tracks[0]?.get('.waveform-chart__axis-endpoint--start').text()).toBe('-8.00')
-    expect(tracks[0]?.get('.waveform-chart__axis-endpoint--end').text()).toBe('5.00')
-    expect(tracks[1]?.get('.waveform-chart__axis-endpoint--start').text()).toBe('-8.00')
-    expect(tracks[1]?.get('.waveform-chart__axis-endpoint--end').text()).toBe('5.00')
+    expect(tracks[0]?.get('.waveform-chart__axis-endpoint--start').text()).toBe('-8000')
+    expect(tracks[0]?.get('.waveform-chart__axis-endpoint--end').text()).toBe('5000')
+    expect(tracks[1]?.get('.waveform-chart__axis-endpoint--start').text()).toBe('-8000')
+    expect(tracks[1]?.get('.waveform-chart__axis-endpoint--end').text()).toBe('5000')
   })
 
   it('uses an explicit initial x domain override for an independent track', async () => {
@@ -293,7 +293,7 @@ describe('WaveformChart', () => {
       },
     )
 
-    expect(wrapper.get('.waveform-chart__axis-endpoint--end').text()).toBe('1.00')
+    expect(wrapper.get('.waveform-chart__axis-endpoint--end').text()).toBe('1000')
   })
 
   it('reacts to exact fixed Y-domain props and returns to automatic bounds', async () => {
@@ -312,13 +312,13 @@ describe('WaveformChart', () => {
 
     await wrapper.setProps({ yDomain: [3, 97] })
     await flushPromises()
-    expect(yTickLabels()).toContain('3.00')
-    expect(yTickLabels()).toContain('97.00')
+    expect(yTickLabels()).toContain('3')
+    expect(yTickLabels()).toContain('97')
 
     await wrapper.setProps({ yDomain: undefined })
     await flushPromises()
-    expect(yTickLabels()).not.toContain('3.00')
-    expect(yTickLabels()).not.toContain('97.00')
+    expect(yTickLabels()).not.toContain('3')
+    expect(yTickLabels()).not.toContain('97')
   })
 
   it('keeps annotations bound to their channel while paging', async () => {
diff --git a/src/components/waveformChartCases/multiAxisAndPagination.test.ts b/src/components/waveformChartCases/multiAxisAndPagination.test.ts
index 8fee69a..2a04a84 100644
--- a/src/components/waveformChartCases/multiAxisAndPagination.test.ts
+++ b/src/components/waveformChartCases/multiAxisAndPagination.test.ts
@@ -30,7 +30,7 @@ describe('WaveformChart', () => {
               kind: 'points',
               points: [
                 { x: 0, y: 0 },
-                { x: 1, y: 254 },
+                { x: 1, y: 2540 },
               ],
             },
           },
@@ -51,13 +51,13 @@ describe('WaveformChart', () => {
     )
 
     expect(
-      wrapper
-        .findAll('.waveform-chart__axis-exponent--y')
-        .map((label) => [label.attributes('data-y-axis-index'), label.text()]),
-    ).toEqual([
-      ['1', 'E+02'],
-      ['2', 'E-04'],
-    ])
+      wrapper.findAll('.waveform-chart__axis--y').map((axis) =>
+        axis
+          .findAll('.tick text')
+          .map((label) => label.text())
+          .filter((label) => label.startsWith('E')),
+      ),
+    ).toEqual([[], [expect.stringMatching(/^E\+03 /)], [expect.stringMatching(/^E-04 /)]])
   })
 
   it('reprojects annotations with the Y axis assigned to their series', async () => {
diff --git a/src/components/waveformChartCases/presentationAndAxes.test.ts b/src/components/waveformChartCases/presentationAndAxes.test.ts
index 8f0917b..f9637fb 100644
--- a/src/components/waveformChartCases/presentationAndAxes.test.ts
+++ b/src/components/waveformChartCases/presentationAndAxes.test.ts
@@ -54,8 +54,9 @@ describe('WaveformChart', () => {
       ],
     })
 
-    expect(first.find('.waveform-chart__axis-exponent--y').exists()).toBe(false)
-    expect(second.get('.waveform-chart__axis-exponent--y').text()).toBe('E+04')
+    expect(first.get('.waveform-chart__axis--y').text()).not.toContain('E')
+    expect(second.get('.waveform-chart__axis--y').text()).toContain('E+04 ')
+    expect(second.find('.waveform-chart__axis-exponent--y').exists()).toBe(false)
   })
 
   it('renders a configurable zero line only when the Y domain contains zero', async () => {
@@ -299,8 +300,9 @@ describe('WaveformChart', () => {
     })
     expect(xAxis.get('path.domain').attributes('display')).toBe('none')
     expect(wrapper.findAll('.waveform-chart__axis-endpoint')).toHaveLength(2)
-    expect(wrapper.get('.waveform-chart__axis-exponent--x').text()).not.toBe('')
-    expect(wrapper.get('.waveform-chart__axis-exponent--y').text()).not.toBe('')
+    expect(wrapper.find('.waveform-chart__axis-exponent--x').exists()).toBe(false)
+    expect(yAxes.some((axis) => axis.text().includes('E+04 '))).toBe(true)
+    expect(wrapper.find('.waveform-chart__axis-exponent--y').exists()).toBe(false)
     expect(wrapper.find('.waveform-chart__grid').exists()).toBe(false)
     expect(wrapper.get('.waveform-chart__plot-frame').attributes()).toMatchObject({
       stroke: '#dc2626',
diff --git a/src/components/waveformChartCases/viewportConstraintsAndReset.test.ts b/src/components/waveformChartCases/viewportConstraintsAndReset.test.ts
index f9c777d..def3de2 100644
--- a/src/components/waveformChartCases/viewportConstraintsAndReset.test.ts
+++ b/src/components/waveformChartCases/viewportConstraintsAndReset.test.ts
@@ -79,8 +79,8 @@ describe('WaveformChart', () => {
 
     expect(wrapper.emitted('zoom-change')).toBeUndefined()
     expect(wrapper.emitted('zoom-end')).toBeUndefined()
-    expect(wrapper.get('.waveform-chart__axis-endpoint--start').text()).toBe('0.00')
-    expect(wrapper.get('.waveform-chart__axis-endpoint--end').text()).toBe('2.00')
+    expect(wrapper.get('.waveform-chart__axis-endpoint--start').text()).toBe('0')
+    expect(wrapper.get('.waveform-chart__axis-endpoint--end').text()).toBe('2000')
   })
 
   it('ignores independent viewport dragging', async () => {
@@ -333,14 +333,14 @@ describe('WaveformChart', () => {
     )
     flushAnimationFrames()
     await flushPromises()
-    expect(wrapper.get('.waveform-chart__axis-endpoint--start').text()).not.toBe('0.00')
+    expect(wrapper.get('.waveform-chart__axis-endpoint--start').text()).not.toBe('0')
 
     overlay.element.dispatchEvent(new MouseEvent('dblclick', { bubbles: true, cancelable: true }))
     await flushPromises()
 
     expect(wrapper.emitted('zoom-reset')).toHaveLength(1)
-    expect(wrapper.get('.waveform-chart__axis-endpoint--start').text()).toBe('0.00')
-    expect(wrapper.get('.waveform-chart__axis-endpoint--end').text()).toBe('2.00')
+    expect(wrapper.get('.waveform-chart__axis-endpoint--start').text()).toBe('0')
+    expect(wrapper.get('.waveform-chart__axis-endpoint--end').text()).toBe('2000')
   })
 
   it('exposes resetViewport for independent tracks', async () => {
@@ -364,13 +364,13 @@ describe('WaveformChart', () => {
     )
     flushAnimationFrames()
     await flushPromises()
-    expect(wrapper.findAll('.waveform-chart__axis-endpoint--start')[0].text()).not.toBe('0.00')
+    expect(wrapper.findAll('.waveform-chart__axis-endpoint--start')[0].text()).not.toBe('0')
 
     const chart = wrapper.vm as unknown as { resetViewport: () => void }
     chart.resetViewport()
     await flushPromises()
 
-    expect(wrapper.findAll('.waveform-chart__axis-endpoint--start')[0].text()).toBe('0.00')
-    expect(wrapper.findAll('.waveform-chart__axis-endpoint--end')[0].text()).toBe('1.00')
+    expect(wrapper.findAll('.waveform-chart__axis-endpoint--start')[0].text()).toBe('0')
+    expect(wrapper.findAll('.waveform-chart__axis-endpoint--end')[0].text()).toBe('1000')
   })
 })
diff --git a/src/components/waveformChartCases/wheelZoomOut.test.ts b/src/components/waveformChartCases/wheelZoomOut.test.ts
index ff54759..0127984 100644
--- a/src/components/waveformChartCases/wheelZoomOut.test.ts
+++ b/src/components/waveformChartCases/wheelZoomOut.test.ts
@@ -49,15 +49,15 @@ describe('WaveformChart wheel zoom out', () => {
       end: wrapper.get('.waveform-chart__axis-endpoint--end').text(),
     })
 
-    expect(endpoints()).toEqual({ start: '-5.00', end: '5.00' })
+    expect(endpoints()).toEqual({ start: '-5000', end: '5000' })
     await dispatchWheel(-4000)
-    expect(endpoints()).not.toEqual({ start: '-5.00', end: '5.00' })
+    expect(endpoints()).not.toEqual({ start: '-5000', end: '5000' })
 
     await wrapper.setProps({ data: createData(-0.125, 0.125) })
     await flushPromises()
     await dispatchWheel(4000)
 
-    expect(endpoints()).toEqual({ start: '-5.00', end: '5.00' })
+    expect(endpoints()).toEqual({ start: '-5000', end: '5000' })
   })
 
   it('emits one zoom-end payload after zooming a shared viewport out', async () => {
diff --git a/src/utils/formatters.test.ts b/src/utils/formatters.test.ts
index 40078f9..7115034 100644
--- a/src/utils/formatters.test.ts
+++ b/src/utils/formatters.test.ts
@@ -3,69 +3,78 @@ import { describe, expect, it } from 'vitest'
 import {
   formatAnnotationTime,
   formatAxisTime,
-  formatAxisTimeExponent,
   formatEndpointTime,
   formatPlainNumber,
   formatScientificAxisExponent,
   formatScientificAxisLabel,
   formatTooltipNumber,
+  formatTooltipTime,
+  resolveScientificAxisExponent,
   shouldUseScientificAxisLabel,
 } from './formatters'
 
 describe('waveform number formatters', () => {
   it('uses the reference Y-axis scientific notation boundaries', () => {
     expect(shouldUseScientificAxisLabel(0)).toBe(false)
-    expect(shouldUseScientificAxisLabel(0.009)).toBe(true)
-    expect(shouldUseScientificAxisLabel(0.01)).toBe(false)
-    expect(shouldUseScientificAxisLabel(99.99)).toBe(false)
-    expect(shouldUseScientificAxisLabel(100)).toBe(true)
+    expect(shouldUseScientificAxisLabel(0.000999)).toBe(true)
+    expect(shouldUseScientificAxisLabel(0.001)).toBe(false)
+    expect(shouldUseScientificAxisLabel(999.999)).toBe(false)
+    expect(shouldUseScientificAxisLabel(1000)).toBe(true)
   })
 
-  it('shares one separate exponent across an axis', () => {
-    const positiveAxis = { axisMin: 0, axisMax: 254 }
-    expect(formatScientificAxisLabel(127, positiveAxis)).toBe('1.27')
-    expect(formatScientificAxisLabel(254, positiveAxis)).toBe('2.54')
-    expect(formatScientificAxisExponent(0, 254)).toBe('E+02')
+  it('prefixes one shared exponent to the largest visible tick', () => {
+    const positiveAxis = { axisMin: 1000, axisMax: 3000 }
+    expect(formatScientificAxisLabel(1000, positiveAxis)).toBe('1')
+    expect(formatScientificAxisLabel(2000, positiveAxis)).toBe('2')
+    expect(formatScientificAxisLabel(3000, positiveAxis)).toBe('E+03 3')
+    expect(formatScientificAxisLabel(2000, { ...positiveAxis, topTickValue: 2000 })).toBe('E+03 2')
+    expect(formatScientificAxisExponent(1000, 3000)).toBe('E+03')
     expect(formatScientificAxisExponent(0, 1e120)).toBe('E+120')
 
-    const tinyAxis = { axisMin: 0, axisMax: 0.0002 }
-    expect(formatScientificAxisLabel(0.0001, tinyAxis)).toBe('1.00')
-    expect(formatScientificAxisLabel(0.0002, tinyAxis)).toBe('2.00')
-    expect(formatScientificAxisExponent(0, 0.0002)).toBe('E-04')
-
-    const negativeAxis = { axisMin: -254, axisMax: 0 }
-    expect(formatScientificAxisLabel(-254, negativeAxis)).toBe('-2.54')
-    expect(formatScientificAxisLabel(0, negativeAxis)).toBe('0.00')
-    expect(formatScientificAxisExponent(-254, 0)).toBe('E+02')
+    const tinyAxis = { axisMin: 0.0001, axisMax: 0.0003 }
+    expect(formatScientificAxisLabel(0.0001, tinyAxis)).toBe('1')
+    expect(formatScientificAxisLabel(0.0002, tinyAxis)).toBe('2')
+    expect(formatScientificAxisLabel(0.0003, tinyAxis)).toBe('E-04 3')
+    expect(formatScientificAxisExponent(0.0001, 0.0003)).toBe('E-04')
   })
 
-  it('keeps plain axes at two decimals and removes negative zero', () => {
-    expect(formatScientificAxisLabel(99.99, { axisMin: 0, axisMax: 99.99 })).toBe('99.99')
-    expect(formatScientificAxisLabel(0.01, { axisMin: 0, axisMax: 0.01 })).toBe('0.01')
-    expect(formatScientificAxisLabel(-0.001, { axisMin: -1, axisMax: 1 })).toBe('0.00')
+  it('derives the exponent from Math.max(axisMin, axisMax)', () => {
+    expect(resolveScientificAxisExponent(-9000, -1000)).toBe(3)
+    expect(resolveScientificAxisExponent(-10_000, 3000)).toBe(3)
+    expect(resolveScientificAxisExponent(-1000, 0)).toBeNull()
+    expect(resolveScientificAxisExponent(0, 0)).toBeNull()
+  })
+
+  it('keeps five significant digits, removes trailing zeroes, and limits decimals to four', () => {
+    expect(formatScientificAxisLabel(123.456, { axisMin: 0, axisMax: 999 })).toBe('123.46')
+    expect(formatScientificAxisLabel(1234.56, { axisMin: 0, axisMax: 9999 })).toBe('1.2346')
+    expect(formatScientificAxisLabel(3000, { axisMin: 1000, axisMax: 3000 })).toBe('E+03 3')
+    expect(formatScientificAxisLabel(-0, { axisMin: -1, axisMax: 1 })).toBe('0')
     expect(formatScientificAxisLabel(Number.NaN)).toBe('NaN')
     expect(formatScientificAxisLabel(Number.POSITIVE_INFINITY)).toBe('Infinity')
     expect(formatScientificAxisExponent(0, 0)).toBeNull()
   })
 
-  it('formats X-axis ticks and endpoints from the selected display unit', () => {
+  it('formats X-axis ticks and endpoints as plain integers in the selected display unit', () => {
     const domain: [number, number] = [0, 1]
-    expect(formatAxisTime(0.5, 'ms', domain)).toBe('0.50')
-    expect(formatEndpointTime(1, domain, 'ms')).toBe('1.00')
-    expect(formatAxisTimeExponent(domain, 'ms')).toBe('E+03')
-    expect(formatAxisTime(0.5, 's', domain)).toBe('0.50')
-    expect(formatEndpointTime(1, domain, 's')).toBe('1.00')
-    expect(formatAxisTimeExponent(domain, 's')).toBeNull()
+    expect(formatAxisTime(0.5004, 'ms', domain)).toBe('500')
+    expect(formatEndpointTime(1, domain, 'ms')).toBe('1000')
+    expect(formatAxisTime(0.5, 's', domain)).toBe('1')
+    expect(formatEndpointTime(1, domain, 's')).toBe('1')
 
     const tinyDomain: [number, number] = [0, 0.000001]
-    expect(formatEndpointTime(0.000001, tinyDomain, 's')).toBe('1.00')
-    expect(formatAxisTimeExponent(tinyDomain, 's')).toBe('E-06')
+    expect(formatEndpointTime(0.000001, tinyDomain, 's')).toBe('0')
+    expect(formatAxisTime(-0.000001, 's', tinyDomain)).toBe('0')
+    expect(formatAxisTime(1e21, 's')).toBe('1000000000000000000000')
+    expect(formatAxisTime(Number.POSITIVE_INFINITY, 's')).toBe('Infinity')
   })
 
   it('formats tooltip and raw values for their display contexts', () => {
     expect(formatTooltipNumber(12345.67891)).toBe('12,345.6789')
     expect(formatTooltipNumber(-0)).toBe('0')
     expect(formatTooltipNumber(Number.POSITIVE_INFINITY)).toBe('Infinity')
+    expect(formatTooltipTime(1.234567, 's')).toBe('1.2346')
+    expect(formatTooltipTime(1, 'ms')).toBe('1,000')
     expect(formatPlainNumber(0.0000001)).toBe('0.0000001')
     expect(formatPlainNumber(1e21)).toBe('1000000000000000000000')
     expect(formatPlainNumber(-0)).toBe('0')
diff --git a/src/utils/formatters.ts b/src/utils/formatters.ts
index 62bf9ed..70d8b4d 100644
--- a/src/utils/formatters.ts
+++ b/src/utils/formatters.ts
@@ -4,22 +4,28 @@
 export type TimeUnit = 'ms' | 's'
 
 export interface ScientificAxisLabelOptions {
+  /** @deprecated Y-axis labels always use five significant digits before localization. */
   precision?: number
   axisMin?: number
   axisMax?: number
-}
-
-/** @deprecated Use ScientificAxisLabelOptions. */
-export type ScientificYAxisLabelOptions = ScientificAxisLabelOptions & {
   topTickValue?: number
 }
 
-const DEFAULT_Y_AXIS_PRECISION = 2
-const SCIENTIFIC_MIN_ABSOLUTE_VALUE = 0.01
-const SCIENTIFIC_MAX_PLAIN_ABSOLUTE_VALUE = 100
+/** @deprecated Use ScientificAxisLabelOptions. */
+export type ScientificYAxisLabelOptions = ScientificAxisLabelOptions
+
+const SCIENTIFIC_MIN_ABSOLUTE_VALUE = 0.001
+const SCIENTIFIC_MAX_PLAIN_ABSOLUTE_VALUE = 1000
+const Y_AXIS_NUMBER_FORMATTER = new Intl.NumberFormat('zh-CN', {
+  maximumFractionDigits: 4,
+})
 const TOOLTIP_NUMBER_FORMATTER = new Intl.NumberFormat('zh-CN', {
   maximumFractionDigits: 4,
 })
+const X_AXIS_TIME_FORMATTER = new Intl.NumberFormat('zh-CN', {
+  maximumFractionDigits: 0,
+  useGrouping: false,
+})
 
 function formatFixedNumber(value: number, precision: number): string {
   const formatted = value.toFixed(Math.max(0, precision))
@@ -38,9 +44,10 @@ export function shouldUseScientificAxisLabel(maxAbsoluteValue: number): boolean
 export function resolveScientificAxisExponent(axisMin?: number, axisMax?: number): number | null {
   if (typeof axisMin !== 'number' || typeof axisMax !== 'number') return null
 
-  const maxAbsoluteValue = Math.max(Math.abs(axisMin), Math.abs(axisMax))
-  return shouldUseScientificAxisLabel(maxAbsoluteValue)
-    ? Math.floor(Math.log10(maxAbsoluteValue))
+  const maxValue = Math.max(axisMin, axisMax)
+  const absoluteMaxValue = Math.abs(maxValue)
+  return shouldUseScientificAxisLabel(absoluteMaxValue)
+    ? Math.floor(Math.log10(absoluteMaxValue))
     : null
 }
 
@@ -49,6 +56,13 @@ function formatExponent(exponent: number): string {
   return `E${sign}${Math.abs(exponent).toString().padStart(2, '0')}`
 }
 
+function formatYAxisNumber(value: number): string {
+  if (Object.is(value, -0)) return '0'
+  const roundedValue = value === 0 ? 0 : Number(value.toPrecision(5))
+  const formatted = Y_AXIS_NUMBER_FORMATTER.format(roundedValue)
+  return formatted === '-0' ? '0' : formatted
+}
+
 /** Format a Y-axis tick, sharing one exponent derived from the complete axis domain. */
 export function formatScientificAxisLabel(
   value: number,
@@ -56,10 +70,13 @@ export function formatScientificAxisLabel(
 ): string {
   if (!Number.isFinite(value)) return String(value)
 
-  const precision = options.precision ?? DEFAULT_Y_AXIS_PRECISION
   const exponent = resolveScientificAxisExponent(options.axisMin, options.axisMax)
   const scaledValue = exponent === null ? value : value / 10 ** exponent
-  return formatFixedNumber(scaledValue, precision)
+  const formattedValue = formatYAxisNumber(scaledValue)
+  const topTickValue = options.topTickValue ?? options.axisMax
+  return exponent !== null && value === topTickValue
+    ? `${formatExponent(exponent)} ${formattedValue}`
+    : formattedValue
 }
 
 /** Return the shared E-style multiplier for an axis, or null for a plain axis. */
@@ -86,6 +103,13 @@ export function formatTooltipNumber(value: number): string {
   return TOOLTIP_NUMBER_FORMATTER.format(value)
 }
 
+/** Format an X-axis time value as a plain integer without grouping separators. */
+function formatAxisTimeValue(value: number): string {
+  if (!Number.isFinite(value)) return String(value)
+  const formatted = X_AXIS_TIME_FORMATTER.format(value)
+  return formatted === '-0' ? '0' : formatted
+}
+
 /** Convert a number to complete plain decimal text without forcing exponential notation. */
 export function formatPlainNumber(value: number): string {
   if (!Number.isFinite(value)) return String(value)
@@ -134,54 +158,34 @@ export function endpointFractionDigits(domain: [number, number], timeUnit: TimeU
 }
 
 /**
- * 按完整 X 轴显示域格式化端点时间
+ * 将 X 轴端点时间格式化为当前显示单位下的普通整数
  * @param value 时间值（秒）
- * @param domain 数据域
+ * @param _domain 数据域（为保持现有调用签名而保留）
  * @param timeUnit 时间单位
  * @returns 格式化的时间字符串
  */
 export function formatEndpointTime(
   value: number,
-  domain: [number, number],
+  _domain: [number, number],
   timeUnit: TimeUnit,
 ): string {
-  const [axisMin, axisMax] = domain.map((domainValue) => displayTime(domainValue, timeUnit)) as [
-    number,
-    number,
-  ]
-  return formatScientificAxisLabel(displayTime(value, timeUnit), {
-    axisMin,
-    axisMax,
-  })
+  return formatAxisTimeValue(displayTime(value, timeUnit))
 }
 
 /**
- * 按完整 X 轴显示域格式化时间刻度
+ * 将 X 轴时间刻度格式化为当前显示单位下的普通整数
  * @param value 时间值（秒）
  * @param timeUnit 时间单位
+ * @param _domain 数据域（为保持现有调用签名而保留）
  * @returns 格式化的时间字符串
  */
 export function formatAxisTime(
   value: number,
   timeUnit: TimeUnit,
-  domain?: [number, number],
+  _domain?: [number, number],
 ): string {
-  const displayValue = displayTime(value, timeUnit)
-  const displayDomain = domain?.map((domainValue) => displayTime(domainValue, timeUnit)) as
-    [number, number] | undefined
-  return formatScientificAxisLabel(displayValue, {
-    axisMin: displayDomain?.[0],
-    axisMax: displayDomain?.[1],
-  })
-}
-
-/** Return the shared multiplier for an X-axis domain in its selected display unit. */
-export function formatAxisTimeExponent(
-  domain: [number, number],
-  timeUnit: TimeUnit,
-): string | null {
-  const [axisMin, axisMax] = domain.map((value) => displayTime(value, timeUnit)) as [number, number]
-  return formatScientificAxisExponent(axisMin, axisMax)
+  void _domain
+  return formatAxisTimeValue(displayTime(value, timeUnit))
 }
 
 /**
@@ -191,11 +195,7 @@ export function formatAxisTimeExponent(
  * @returns 格式化的时间字符串
  */
 export function formatTooltipTime(value: number, timeUnit: TimeUnit): string {
-  const displayValue = displayTime(value, timeUnit)
-  return displayValue.toLocaleString('zh-CN', {
-    minimumFractionDigits: 4,
-    maximumFractionDigits: 4,
-  })
+  return formatTooltipNumber(displayTime(value, timeUnit))
 }
 
 /** Format an annotation X coordinate in the selected display time unit. */
diff --git a/src/utils/index.ts b/src/utils/index.ts
index 9377e23..cba43f1 100644
--- a/src/utils/index.ts
+++ b/src/utils/index.ts
@@ -11,7 +11,6 @@ export {
   endpointFractionDigits,
   formatEndpointTime,
   formatAxisTime,
-  formatAxisTimeExponent,
   formatTooltipTime,
   formatAnnotationTime,
   formatPlainNumber,