散点图把值编码为两个定量轴上点的位置。赫歇尔点绘轨道；高尔顿 1880 年代回归使该形式成名。
工作报告、广告与作业中适合两个度量的相关、离群与聚类。若一轴非定量，或时间才是主线，换一种形式。
Parts
- 标记 — The core mark of 散点图 is 两个定量轴上点的位置.
- 尺度 — The scale must show zero (or a declared break) and units.
- 轴 — Axis titles name the variable, not a mood.
- 图例 — A legend is weaker than a direct label. Write beside the mark when you can.
- 标签 — Numbers are optional. If comparison is the job, label the ends only.
- 网格 — Keep the grid faint. Data should own the ink.
- 注释 — One annotation sentence. Date the source.
- 外框 — A thin frame. Never a 3-D box.
Variants
- XY 图 — Variant 1 of 散点图. Same encoding, different layout.
- 相关图 — Variant 2 of 散点图. Same encoding, different layout.
- 点云 — Variant 3 of 散点图. Same encoding, different layout.
- 散点图 4 — Variant 4 of 散点图. Same encoding, different layout.
Labels
- 轴 — On 散点图, make Mark readable.
- 图例 — On 散点图, make Scale readable.
- 标签 — On 散点图, make Axis readable.
- 网格 — On 散点图, make Legend readable.
- 注释 — On 散点图, make Label readable.
散点图: honour 两个定量轴上点的位置, and switch when 一轴非定量，或时间才是主线.