83 lines
3.3 KiB
JavaScript
83 lines
3.3 KiB
JavaScript
// Copyright (c) 2001-2010, Purdue University. All rights reserved.
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// Copyright (C) 2015 Apple Inc. All rights reserved.
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//
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// Redistribution and use in source and binary forms, with or without
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// modification, are permitted provided that the following conditions are met:
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// * Redistributions of source code must retain the above copyright
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// notice, this list of conditions and the following disclaimer.
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// * Redistributions in binary form must reproduce the above copyright
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// notice, this list of conditions and the following disclaimer in the
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// documentation and/or other materials provided with the distribution.
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// * Neither the name of the Purdue University nor the
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// names of its contributors may be used to endorse or promote products
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// derived from this software without specific prior written permission.
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//
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// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
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// ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
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// WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
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// DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE FOR ANY
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// DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
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// (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
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// LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
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// ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
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// SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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function compareNumbers(a, b) {
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if (a == b)
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return 0;
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if (a < b)
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return -1;
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if (a > b)
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return 1;
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// We say that NaN is smaller than non-NaN.
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if (a == a)
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return 1;
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return -1;
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}
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function averageAbovePercentile(numbers, percentile) {
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// Don't change the original array.
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numbers = numbers.slice();
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// Sort in ascending order.
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numbers.sort(function(a, b) { return a - b; });
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// Now the elements we want are at the end. Keep removing them until the array size shrinks too much.
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// Examples assuming percentile = 99:
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//
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// - numbers.length starts at 100: we will remove just the worst entry and then not remove anymore,
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// since then numbers.length / originalLength = 0.99.
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//
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// - numbers.length starts at 1000: we will remove the ten worst.
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//
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// - numbers.length starts at 10: we will remove just the worst.
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var numbersWeWant = [];
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var originalLength = numbers.length;
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while (numbers.length / originalLength > percentile / 100)
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numbersWeWant.push(numbers.pop());
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var sum = 0;
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for (var i = 0; i < numbersWeWant.length; ++i)
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sum += numbersWeWant[i];
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var result = sum / numbersWeWant.length;
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// Do a sanity check.
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if (numbers.length && result < numbers[numbers.length - 1]) {
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throw "Sanity check fail: the worst case result is " + result +
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" but we didn't take into account " + numbers;
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}
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return result;
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}
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var currentTime;
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if (this.performance && performance.now)
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currentTime = function() { return performance.now() };
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else if (preciseTime)
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currentTime = function() { return preciseTime() * 1000; };
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else
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currentTime = function() { return 0 + new Date(); };
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