Grouped / Merged Y-Axes with Multi-Scale Ticks

[ngmikeng]

Feature Request: Grouped / Merged Y-Axes with Multi-Scale Ticks

Summary

Request support for grouping multiple Y-axes into a single visual axis (left/right) while preserving multiple independent tick scales on the same axis line.

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Current Behavior

XChart supports multiple Y-axes via YAxisGroup, but each axis is rendered as a separate axis line.

Example (4 axes):

• Left:

  • Axis1 → 100, 200, 300, 400, 500
  • Axis2 → 1, 2, 3, 4, 5

• Right:

  • Axis3 → 1500, 3000, 4500, 6000
  • Axis4 → 10, 20, 30, 40

This results in 4 visible axis lines.

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Desired Behavior

Allow grouping/merging axes visually so that:

Left (merged):

100, 200, 300, 400, 500
  1,   2,   3,   4,   5

Right (merged):

1500, 3000, 4500, 6000, 7500
  10,   20,   30,   40,   50

Only 2 axis lines (left/right), each showing multiple tick scales, with shared gridlines.

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Why This Is Useful

Important for:

• Multi-unit time series
• QC / monitoring systems

Improves readability and reduces visual clutter in multi-metric charts.

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Expectations

• Single axis line per group
• Multiple tick scales per axis
• Shared gridlines
• Independent scaling per series
• Backward compatible
• Optional feature (off by default)