import { PDG } from './pdg.js';
export type WeightFn = (feature: string) => number;
export declare function unitWeight(_feature: string): number;
export declare function surprisalWeightFromCorpus(pNat: Record<string, number>, floor?: number): WeightFn;
/**
 * Calculates correlation between two PDGs using surprisal-weighted cosine.
 * Matches rcf_core.correlate.correlate in Python.
 */
export declare function correlate(a: PDG, b: PDG, options?: {
    iterations?: number;
    weight?: WeightFn;
}): number;
//# sourceMappingURL=correlate.d.ts.map