D07-F09-A01 · LEVEL 2 GUIDED LAB · SYNTHETIC DATA

Rolling Percentile

What fraction of the current rolling sample lies below the newest value? Walk the evidence clock one stage at a time. This lab teaches the publication contract; it does not simulate returns, platform parity, or trade performance.

Selected expression

percentile_rank_t=100*(count(x_i<x_t)+c*count(x_i=x_t))/N, with tie constant c declared

Availability rule

An output at t may use only finite, basis-consistent observations available through t; chart alignment never moves the information clock backward.

calculated · step 1 of 7

Verified synthetic fixture

This lab is paired with datasets/implementation-fixtures.json: 96 deterministic, oldest-to-newest observations spanning oscillating, rising, and moderating regimes. It is teaching data—not market history or predictive evidence.

Canonical latest output (D07-F09-A01)
{
  "value": 2.5
}

Executable checks cover this result, flat/zero-volume boundaries, invalid timestamps, and prefix causality in both language entry points.