Imports name this capability’s declared dependencies, which fune builds next to it in your project; each one links to its page.
import math
from typing import Sequence
from .math_round_float import round_float ← from math.round-float ^1.0.0 · built alongside by fune
from .stats_percentile_types import PercentileMethod
def _finite(value: object) -> bool:
return isinstance(value, (int, float)) and not isinstance(value, bool) and math.isfinite(value)
def percentile(values: Sequence[float], p: float, method: PercentileMethod, decimals: int) -> float:
"""The p-th percentile of ``values`` by a named method.
There is no single "95th percentile": the caller names the definition, so
a dashboard and a billing job cannot quietly disagree.
"""
if isinstance(values, (str, bytes)) or not isinstance(values, (list, tuple)):
raise TypeError("values must be a list of numbers")
if len(values) == 0:
raise ValueError("values must not be empty")
for v in values:
if not _finite(v):
raise TypeError("values must be finite numbers, received %r" % (v,))
if not _finite(p) or p < 0 or p > 100:
raise ValueError("p must be between 0 and 100, received %r" % (p,))
# Checked up front as well as in round_float (same wording), so a bad
# decimals is reported before the method is looked at, as in 1.x.
if isinstance(decimals, bool) or not isinstance(decimals, int) or decimals < 0 or decimals > 12:
raise ValueError("decimals must be a whole number from 0 to 12, received %r" % (decimals,))
# float() first so integer inputs follow exactly the binary64 path the
# other languages take.
ordered = sorted(float(v) for v in values)
n = len(ordered)
p = float(p)
if method == "nearest-rank":
# The smallest value with at least p% of the sample at or below it.
rank = math.ceil((p * n) / 100.0)
if rank < 1:
rank = 1
result = ordered[rank - 1]
elif method == "linear":
# Hyndman & Fan type 7: zero-based position (n - 1) * p / 100.
h = ((n - 1) * p) / 100.0
lo = math.floor(h)
if lo >= n - 1:
result = ordered[n - 1]
else:
result = ordered[lo] + (h - lo) * (ordered[lo + 1] - ordered[lo])
else:
raise ValueError('unknown percentile method "%s"' % (method,))
# math.round-float rounds on the exact value of the double: 2.675 gives 2.67.
return round_float(result, decimals)