Платформа ЦРНП "Мирокод" для разработки проектов
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39 lines
886 B
39 lines
886 B
// Copyright 2010 Petar Maymounkov. All rights reserved. |
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// Use of this source code is governed by a BSD-style |
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// license that can be found in the LICENSE file. |
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package llrb |
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import "math" |
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// avgVar maintains the average and variance of a stream of numbers |
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// in a space-efficient manner. |
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type avgVar struct { |
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count int64 |
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sum, sumsq float64 |
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} |
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func (av *avgVar) Init() { |
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av.count = 0 |
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av.sum = 0.0 |
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av.sumsq = 0.0 |
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} |
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func (av *avgVar) Add(sample float64) { |
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av.count++ |
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av.sum += sample |
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av.sumsq += sample * sample |
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} |
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func (av *avgVar) GetCount() int64 { return av.count } |
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func (av *avgVar) GetAvg() float64 { return av.sum / float64(av.count) } |
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func (av *avgVar) GetTotal() float64 { return av.sum } |
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func (av *avgVar) GetVar() float64 { |
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a := av.GetAvg() |
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return av.sumsq/float64(av.count) - a*a |
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} |
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func (av *avgVar) GetStdDev() float64 { return math.Sqrt(av.GetVar()) }
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