_percentile

Computes a percentile from a list of floats using linear interpolation, returning 0 for empty input. Useful for summarizing benchmark result distributions.

# Source: https://github.com/Shaivpidadi/FreeRideV3 | License: MIT | Copyright 2026 Shaishav Pidadi
# Provided via justclaw.it.com; keep this notice with the code.
def _percentile(values: list[float], p: float) -> float:
    """Linear-interpolation percentile. Returns 0 for empty input."""
    if not values:
        return 0.0
    s = sorted(values)
    if len(s) == 1:
        return s[0]
    k = (len(s) - 1) * p / 100.0
    f = int(k)
    c = min(f + 1, len(s) - 1)
    if f == c:
        return s[f]
    return s[f] + (s[c] - s[f]) * (k - f)