@livefolio/sdk / evaluateFeatureSpecs

Function: evaluateFeatureSpecs()

evaluateFeatureSpecs(specs, runtime, t): Promise<Map<string, number | undefined>>

Defined in: tactical/evaluate-feature-specs.ts:86

Resolves each TacticalFeatureSpec in specs to a scalar value as of date t by calling into runtime and reading the series at the appropriate bar index. All specs are computed in parallel via Promise.all.

The returned map uses each spec's id as the key. The value is undefined when the indicator series has no data on or before t, or when the delay offset steps past the beginning of the series.

Validation performed before dispatching to the runtime:

• Duplicate id values in specs throw immediately.
• A non-integer or negative delay throws immediately.

Parameters

Parameter	Type	Description
specs	readonly TacticalFeatureSpec[]	Ordered list of feature declarations from TacticalSpec.features.
runtime	FeatureRuntime	Feature computation backend that owns the data feed and cache.
t	Date	Evaluation date; the series is read at the latest bar on or before t.

Returns

Promise<Map<string, number | undefined>>

A map from feature id to resolved numeric value (undefined when unavailable).

Example

import { evaluateFeatureSpecs } from '@livefolio/sdk';
import type { TacticalFeatureSpec } from '@livefolio/sdk';

const specs: TacticalFeatureSpec[] = [
  { id: 'spy_sma200', kind: 'sma', asset: { id: 'SPY', symbol: 'SPY' }, period: 200 },
  { id: 'spy_price',  kind: 'price', asset: { id: 'SPY', symbol: 'SPY' } },
];

const values = await evaluateFeatureSpecs(specs, runtime, new Date('2024-06-01'));
// values.get('spy_price') → 528.3