1 /*
2  * Copyright (C) 2016 The Android Open Source Project
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *      http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 
17 package com.android.rs.imagejb;
18 
19 import java.util.ArrayList;
20 
21 class Result {
22 
23     private ArrayList<Float> timeList;
24 
Result()25     Result() {
26         timeList = new ArrayList<Float>();
27     }
28 
29     // Add time
add(float time)30     public void add(float time) {
31         timeList.add(time);
32     }
33 
34     // Get total execution time
getTotalTime()35     public float getTotalTime() {
36         float total = 0.0f;
37         for (float time : timeList) {
38             total += time;
39         }
40         return total;
41     }
42 
43     // Get number of iterations
getIterations()44     public int getIterations() {
45         return timeList.size();
46     }
47 
48     // Get the average of an array list
getAvg()49     public float getAvg() {
50         return getTotalTime() / getIterations();
51     }
52 
53     // Get the biased ("full population") standard deviation
getStdevp()54     public float getStdevp() {
55         float sumSqDiff = 0;
56         float avg = getAvg();
57         for (float time : timeList) {
58             float diff = time - avg;
59             sumSqDiff += diff * diff;
60         }
61         return (float) Math.sqrt(sumSqDiff / getIterations());
62     }
63 
64     // Get the normalized standard deviation ("standard deviation coefficient")
getStdCoef()65     public float getStdCoef() {
66         return getStdevp() / getAvg();
67     }
68 
69     // Get all times as float[]
getTimes()70     public float[] getTimes() {
71         float[] array = new float[getIterations()];
72         for (int i = 0; i < getIterations(); i++) {
73             array[i] = timeList.get(i);
74         }
75         return array;
76     }
77 }
78