ai_member_xiaobian/.agents/skills/lark-whiteboard/scenes/bar-chart.md
2026-05-15 10:57:05 +08:00

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柱状图

Content 约束

  • 数据点 ≤ 12
  • 同一数据系列用同一颜色(不要每个柱不同色)
  • Y 轴必须有单位标注(如 "万元"、"人次"

Layout 选型

  • 脚本生成坐标(推荐):用 .cjs 脚本计算柱体位置和高度,脚本输出 JSON 文件后调用 npx -y @larksuite/whiteboard-cli@^0.2.10 渲染
  • 绝对定位手写:简单柱状图(≤ 5 个柱)可手写坐标

Layout 规则

  • 白板坐标系 Y 轴向下为正,图表"底部原点"拥有最大 Y 值,柱体向上生长时 Y 减小
  • 柱体等宽等间距,底部对齐 X 轴
  • 柱体高度:height = (value / maxValue) * chartHeight
  • 柱体 Y 坐标:y = originY - height
  • 坐标轴用 connector 直线末端带箭头endArrow: "arrow"
  • 格线用虚线 connectorlineStyle: "dashed"endArrow: "none"
  • 刻度线短横线 connectorendArrow: "none"
  • 数值标注放在柱体顶部上方
  • 类别标签放在 X 轴下方,居中对齐柱体

坐标与尺寸计算指南

白板坐标系中,X 轴向右为正Y 轴向下为正。因此图表的"底部原点"实际上拥有最大的 Y 坐标,图形向上生长时 Y 坐标在不断减小。

  1. 确定图表区域
    • 设定图表区高度 chartHeight 和宽度 chartWidth
    • 设定左下角坐标原点 (originX, originY)
    • 示例originX=80, originY=480, chartWidth=1000, chartHeight=400
  2. Y 轴映射(计算高度)
    • 找出数据的最大值 maxValue
    • 将 maxValue 向上取整到"整数刻度"(如数据最大 190 → maxValue 取 200
    • 柱子高度:height = (value / maxValue) * chartHeight
    • 柱子 Y 坐标:y = originY - height
  3. X 轴映射(计算宽度与 X 坐标)
    • 将 chartWidth 按数据个数均分:slotWidth = chartWidth / barCount
    • 设定柱子间距 barGap(推荐 slotWidth 的 25%-30%
    • 柱子宽度:barWidth = slotWidth - barGap
    • 第 i 根柱子 X 坐标:x = originX + i * slotWidth + barGap / 2
  4. Y 轴刻度计算
    • 将 0 到 maxValue 等分为 4-6 个刻度
    • 每个刻度的 Y 坐标:gridY = originY - (tickValue / maxValue) * chartHeight
    • 刻度线:从 (originX-10, gridY) 到 (originX, gridY) 的短横线
    • 网格线:从 (originX, gridY) 到 (originX+chartWidth, gridY) 的虚线

完整 JSON 示例

以下示例3 根柱子,数据 [120, 200, 150]maxValue=200originX=80, originY=480, chartWidth=900, chartHeight=400。

  • slotWidth = 900 / 3 = 300
  • barGap = 80, barWidth = 220
  • 刻度0, 50, 100, 150, 200每 50 一格gridInterval = 80px
{
  "version": 2,
  "nodes": [
    { "type": "rect", "x": 0, "y": 0, "width": 1100, "height": 580 },

    { "type": "text", "x": 80, "y": 10, "width": 900, "height": "fit-content",
      "text": "季度销售额对比", "fontSize": 24, "textAlign": "center" },

    { "type": "text", "x": 10, "y": 40, "width": 60, "height": "fit-content",
      "text": "万元", "fontSize": 12, "textAlign": "center" },

    { "type": "connector", "connector": {
      "from": { "x": 80, "y": 480 }, "to": { "x": 80, "y": 55 },
      "lineShape": "straight", "lineWidth": 2, "endArrow": "arrow"
    }},
    { "type": "connector", "connector": {
      "from": { "x": 80, "y": 480 }, "to": { "x": 1000, "y": 480 },
      "lineShape": "straight", "lineWidth": 2, "endArrow": "arrow"
    }},

    { "type": "connector", "connector": {
      "from": { "x": 70, "y": 480 }, "to": { "x": 80, "y": 480 },
      "lineShape": "straight", "lineWidth": 1,
      "startArrow": "none", "endArrow": "none"
    }},
    { "type": "text", "x": 20, "y": 470, "width": 50, "height": 20,
      "text": "0", "fontSize": 12, "textAlign": "right" },

    { "type": "connector", "connector": {
      "from": { "x": 70, "y": 400 }, "to": { "x": 80, "y": 400 },
      "lineShape": "straight", "lineWidth": 1,
      "startArrow": "none", "endArrow": "none"
    }},
    { "type": "text", "x": 20, "y": 390, "width": 50, "height": 20,
      "text": "50", "fontSize": 12, "textAlign": "right" },
    { "type": "connector", "connector": {
      "from": { "x": 80, "y": 400 }, "to": { "x": 980, "y": 400 },
      "lineShape": "straight", "lineWidth": 1, "lineStyle": "dashed",
      "startArrow": "none", "endArrow": "none"
    }},

    { "type": "connector", "connector": {
      "from": { "x": 70, "y": 320 }, "to": { "x": 80, "y": 320 },
      "lineShape": "straight", "lineWidth": 1,
      "startArrow": "none", "endArrow": "none"
    }},
    { "type": "text", "x": 20, "y": 310, "width": 50, "height": 20,
      "text": "100", "fontSize": 12, "textAlign": "right" },
    { "type": "connector", "connector": {
      "from": { "x": 80, "y": 320 }, "to": { "x": 980, "y": 320 },
      "lineShape": "straight", "lineWidth": 1, "lineStyle": "dashed",
      "startArrow": "none", "endArrow": "none"
    }},

    { "type": "connector", "connector": {
      "from": { "x": 70, "y": 240 }, "to": { "x": 80, "y": 240 },
      "lineShape": "straight", "lineWidth": 1,
      "startArrow": "none", "endArrow": "none"
    }},
    { "type": "text", "x": 20, "y": 230, "width": 50, "height": 20,
      "text": "150", "fontSize": 12, "textAlign": "right" },
    { "type": "connector", "connector": {
      "from": { "x": 80, "y": 240 }, "to": { "x": 980, "y": 240 },
      "lineShape": "straight", "lineWidth": 1, "lineStyle": "dashed",
      "startArrow": "none", "endArrow": "none"
    }},

    { "type": "connector", "connector": {
      "from": { "x": 70, "y": 160 }, "to": { "x": 80, "y": 160 },
      "lineShape": "straight", "lineWidth": 1,
      "startArrow": "none", "endArrow": "none"
    }},
    { "type": "text", "x": 20, "y": 150, "width": 50, "height": 20,
      "text": "200", "fontSize": 12, "textAlign": "right" },
    { "type": "connector", "connector": {
      "from": { "x": 80, "y": 160 }, "to": { "x": 980, "y": 160 },
      "lineShape": "straight", "lineWidth": 1, "lineStyle": "dashed",
      "startArrow": "none", "endArrow": "none"
    }},

    { "type": "rect", "id": "bar-0", "x": 120, "y": 240,
      "width": 220, "height": 240, "borderRadius": 4 },
    { "type": "text", "x": 120, "y": 215,
      "width": 220, "height": 20,
      "text": "120", "fontSize": 14, "textAlign": "center" },
    { "type": "text", "x": 120, "y": 490,
      "width": 220, "height": 30,
      "text": "Q1", "fontSize": 14, "textAlign": "center" },

    { "type": "rect", "id": "bar-1", "x": 420, "y": 80,
      "width": 220, "height": 400, "borderRadius": 4 },
    { "type": "text", "x": 420, "y": 55,
      "width": 220, "height": 20,
      "text": "200", "fontSize": 14, "textAlign": "center" },
    { "type": "text", "x": 420, "y": 490,
      "width": 220, "height": 30,
      "text": "Q2", "fontSize": 14, "textAlign": "center" },

    { "type": "rect", "id": "bar-2", "x": 720, "y": 180,
      "width": 220, "height": 300, "borderRadius": 4 },
    { "type": "text", "x": 720, "y": 155,
      "width": 220, "height": 20,
      "text": "150", "fontSize": 14, "textAlign": "center" },
    { "type": "text", "x": 720, "y": 490,
      "width": 220, "height": 30,
      "text": "Q3", "fontSize": 14, "textAlign": "center" }
  ]
}

坐标推导验证:

  • bar-0 (120): height = (120/200)*400 = 240, y = 480-240 = 240
  • bar-1 (200): height = (200/200)*400 = 400, y = 480-400 = 80
  • bar-2 (150): height = (150/200)*400 = 300, y = 480-300 = 180
  • bar-0 x = 80 + 0300 + 80/2 = 120, bar-1 x = 80 + 1300 + 40 = 420, bar-2 x = 80 + 2*300 + 40 = 720

陷阱

  • 单系列用多色(不专业):同一数据系列所有柱体应使用同一颜色
  • 缺 Y 轴单位标注,读者无法理解数值含义
  • 柱体间距不均匀(脚本需统一计算 barGap
  • Y 轴刻度线和格线误带箭头
  • 坐标轴忘记带箭头

此场景必须用 .cjs 脚本生成。Agent 使用时只需修改 data 数组,其余坐标与柱体高度全自动计算。

const { writeFileSync } = require('fs');