bridge-chartslisted

# Bridge charts The most valuable chart in finance and the most consistently under-used. A bridge answers *how we got from A to B* — the one question a table of two numbers cannot. Build it with `chartkit.waterfallLayout` (see `svg-charting`), which computes the geometry and, more importantly, checks that the bridge foots. --- ## The rule that comes before any styling > **The bars must sum exactly to the closing anchor.** If they do not, the decomposition is wrong. Fix the analysis. **Never add a plug, never quietly widen "other", never adjust the closing anchor to match.** A bridge that foots because of a plug is a chart that asserts a false explanation. ```js const {bars, domain, footing} = chartkit.waterfallLayout(items); if (footing && !footing.ok) { throw new Error(`Bridge does not foot by ${footing.variance} — fix the analysis`); } ``` Fail loudly. A silent plug is the single worst failure mode in financial charting because it is invisible in the output. --- ## Anatomy | Bar type | Sits | Encodes | |---|---|---| | **Anchor** | On the baseline | An absolute state — opening, closing | | **Delta** | Floating, from the running total | A change | | **Subtotal** | On the baseline | The running total at a stage | ``` ┌───┐ ┌───┐ │ │ ┌──┐ │ │ ┌───┐ │ │ │ │ ┌──┐ │ │ │ │──┘ └──┘ └──┘ └──┐ ┌──┐ │ │ │ │ └───┘ └───────