# Function zScore

- zScore(value: number, baseline: BaselineSummary): number

  Single-sample z-score with a guard for zero variance.

  When `stdev` is zero (single data point or constant series) the z-score is undefined; this helper returns `0` so callers can treat constant series as "no anomaly" without special-casing.

  #### Parameters

  - value: number
  - baseline: BaselineSummary

  #### Returns number

  - Defined in utils/votingBaseline.ts:402