Function useDerived

useDerived<S extends SeriesSchema, R>(
series: TimeSeries<S> | null,
transform: (series: TimeSeries<S>) => R,
): R | null
Apply a batch transform to a TimeSeries snapshot, recomputing only when the input snapshot changes.

The transform function should be referentially stable (wrap in useCallback if it captures changing dependencies). Returns null when the input snapshot is null.
Type Parameters
- S extends SeriesSchema
- R
Parameters
- series: TimeSeries<S> | null
- transform: (series: TimeSeries<S>) => R
Returns R | null
Example
```
const [, snapshot] = useLiveSeries(opts);
const smoothed = useDerived(snapshot, (s) =>
  s.smooth('cpu', 'ema', { alpha: 0.2 }),
);
```
- Defined in react/src/useDerived.ts:20