| <!DOCTYPE html> |
| <!-- |
| Copyright (c) 2015 The Chromium Authors. All rights reserved. |
| Use of this source code is governed by a BSD-style license that can be |
| found in the LICENSE file. |
| --> |
| <link rel="import" href="/tracing/model/user_model/user_expectation.html"> |
| |
| <script> |
| 'use strict'; |
| |
| tr.exportTo('tr.metrics.sh', function() { |
| // Returns a weight for this score. |
| // score should be a number between 0 and 1 inclusive. |
| // This function is expected to be passed to tr.b.Statistics.weightedMean as |
| // its weightCallback. |
| function perceptualBlend(ir, index, score) { |
| // Lower scores are exponentially more important than higher scores |
| // due to the Peak-end rule. |
| // Other than that general rule, there is no specific reasoning behind this |
| // specific formula -- it is fairly arbitrary. |
| return Math.exp(1 - score); |
| } |
| |
| function filterExpectationsByRange(irs, opt_range) { |
| var filteredExpectations = []; |
| irs.forEach(function(ir) { |
| if (!(ir instanceof tr.model.um.UserExpectation)) |
| return; |
| |
| if (!opt_range || |
| opt_range.intersectsExplicitRangeExclusive(ir.start, ir.end)) |
| filteredExpectations.push(ir); |
| }); |
| return filteredExpectations; |
| } |
| |
| return { |
| perceptualBlend: perceptualBlend, |
| filterExpectationsByRange: filterExpectationsByRange |
| }; |
| }); |
| </script> |
