reimplement percentile function

pull/14795/head
Jan Tattermusch 7 years ago
parent b4a5727149
commit 577e637920
  1. 22
      tools/profiling/latency_profile/profile_analyzer.py

@ -184,24 +184,24 @@ for cs in call_stacks:
def percentile(N, percent, key=lambda x: x):
"""
Find the percentile of a list of values.
Find the percentile of an already sorted list of values.
@parameter N - is a list of values. Note N MUST BE already sorted.
@parameter percent - a float value from 0.0 to 1.0.
@parameter N - is a list of values. MUST be already sorted.
@parameter percent - a float value from [0.0,1.0].
@parameter key - optional key function to compute value from each element of N.
@return - the percentile of the values
"""
if not N:
return None
k = (len(N) - 1) * percent
f = math.floor(k)
c = math.ceil(k)
if f == c:
return key(N[int(k)])
d0 = key(N[int(f)]) * (c - k)
d1 = key(N[int(c)]) * (k - f)
return d0 + d1
idx = (len(N) - 1) * percent
idx_floor = math.floor(idx)
idx_ceil = math.ceil(idx)
if idx_floor != idx_ceil:
# interpolate the nearest element values
return (key(N[int(idx_floor)]) * (idx_ceil - idx) +
key(N[int(idx_ceil)]) * (idx - idx_floor))
return key(N[int(idx)])
def tidy_tag(tag):

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