How chart selection works
After SQL execution, Chion evaluates the result shape to select the best chart type. The system scores 8 chart variants across the line and bar families — single line, multi-series line, dual-axis line, stacked area, standard bar, grouped bar, stacked bar, and animated bar race.
Compatibility scoring
Each chart type has a compatibility function that scores the match:
- ≥0.7: strong match — use this chart
- ≥0.4: acceptable — use if no stronger match exists
- <0.4: rejected
Selection is deterministic
Same data shape always produces the same chart type. The fallback chain is: line → bar → scatter → table.
Dual-axis and multi-series
Dual-axis layouts are assigned automatically based on series count and scale divergence. If two metrics have different magnitudes (e.g., revenue in millions vs. count in hundreds), they get separate Y axes.
Why the SQL is always visible
Every chart in Chion shows the exact SQL query underneath. This isn't optional — it's the core design principle. If you can't see the SQL, you can't trust the chart. If you can't trace the number, you shouldn't put it in a slide deck.
Interactive features
All charts support: zoom, pan, tooltip hover, series toggle, responsive resize, and export. Charts are rendered with D3.js for maximum flexibility — no abstraction layer between the data and the pixels.