1#!/usr/bin/env python3
2#
3# Copyright 2017 gRPC authors.
4#
5# Licensed under the Apache License, Version 2.0 (the "License");
6# you may not use this file except in compliance with the License.
7# You may obtain a copy of the License at
8#
9#     http://www.apache.org/licenses/LICENSE-2.0
10#
11# Unless required by applicable law or agreed to in writing, software
12# distributed under the License is distributed on an "AS IS" BASIS,
13# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14# See the License for the specific language governing permissions and
15# limitations under the License.
16
17import math
18
19from scipy import stats
20
21_DEFAULT_THRESHOLD = 1e-10
22
23
24def scale(a, mul):
25    return [x * mul for x in a]
26
27
28def cmp(a, b):
29    return stats.ttest_ind(a, b)
30
31
32def speedup(new, old, threshold=_DEFAULT_THRESHOLD):
33    if (len(set(new))) == 1 and new == old:
34        return 0
35    s0, p0 = cmp(new, old)
36    if math.isnan(p0):
37        return 0
38    if s0 == 0:
39        return 0
40    if p0 > threshold:
41        return 0
42    if s0 < 0:
43        pct = 1
44        while pct < 100:
45            sp, pp = cmp(new, scale(old, 1 - pct / 100.0))
46            if sp > 0:
47                break
48            if pp > threshold:
49                break
50            pct += 1
51        return -(pct - 1)
52    else:
53        pct = 1
54        while pct < 10000:
55            sp, pp = cmp(new, scale(old, 1 + pct / 100.0))
56            if sp < 0:
57                break
58            if pp > threshold:
59                break
60            pct += 1
61        return pct - 1
62
63
64if __name__ == "__main__":
65    new = [0.0, 0.0, 0.0, 0.0]
66    old = [2.96608e-06, 3.35076e-06, 3.45384e-06, 3.34407e-06]
67    print(speedup(new, old, 1e-5))
68    print(speedup(old, new, 1e-5))
69