File size: 2,551 Bytes
fc0f7bd | 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 | import { IMetricResponse, IMetricRequest } from "./IFairnessProps";
import { ParityModes } from "./ParityMetrics";
export class MetricsCache {
private static readonly defaultKeys = ["falsePositiveRate", "falseNegativeRate"];
// Top index is featureBin index, second index is model index. Third string key is metricKey
private cache: Array<Array<{[key: string]: IMetricResponse}>>;
constructor(private featureCount: number,
private numberOfModels: number,
private fetchMethod: (request: IMetricRequest) => Promise<IMetricResponse>) {
this.cache = new Array(featureCount).fill(0).map(y => new Array(numberOfModels).fill(0).map(x => {return {};}));
}
public async getMetric(binIndexVector: number[], featureIndex: number, modelIndex: number, key: string): Promise<IMetricResponse> {
let value = this.cache[featureIndex][modelIndex][key];
if (value === undefined) {
value = await this.fetchMethod({
metricKey:key,
binVector: binIndexVector,
modelIndex: modelIndex
});
this.cache[featureIndex][modelIndex][key] = value;
}
return this.cache[featureIndex][modelIndex][key];
}
public async getDisparityMetric(binIndexVector: number[], featureIndex: number, modelIndex: number, key: string, disparityMethod: ParityModes): Promise<number> {
let value = this.cache[featureIndex][modelIndex][key];
if (value === undefined) {
value = await this.fetchMethod({
metricKey: key,
binVector: binIndexVector,
modelIndex: modelIndex
});
this.cache[featureIndex][modelIndex][key] = value;
}
const bins = value.bins.slice().filter(x => x !== undefined && !isNaN(x));
const min = Math.min(...(bins as number[]));
const max = Math.max(...(bins as number[]));
if (isNaN(min) || isNaN(max) || (max === 0 && disparityMethod === ParityModes.ratio)) {
return Number.NaN;
}
return disparityMethod === ParityModes.difference ?
max - min :
min / max;
}
public clearCache(binIndex?: number): void {
if (binIndex !== undefined) {
this.cache[binIndex] = new Array(this.numberOfModels).fill(0).map(x => {return {};});
} else {
this.cache = new Array(this.featureCount).fill(0).map(y => new Array(this.numberOfModels).fill(0).map(x => {return {};}));
}
}
} |