37 lines
1.0 KiB
Go
37 lines
1.0 KiB
Go
// CookieJar - A contestant's algorithm toolbox
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// Copyright (c) 2014 Peter Szilagyi. All rights reserved.
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//
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// CookieJar is dual licensed: use of this source code is governed by a BSD
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// license that can be found in the LICENSE file. Alternatively, the CookieJar
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// toolbox may be used in accordance with the terms and conditions contained
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// in a signed written agreement between you and the author(s).
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package curves
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import (
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"math"
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"gopkg.in/karalabe/cookiejar.v2/ai/utility"
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)
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// Exponential curve builder. Defined as y = |x-infl| ^ exp.
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type Exponential struct {
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Infl float64 // Point of inflection (either peek of valley)
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Exp float64 // Exponent defining the rate of change
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Convex bool // Switches between upwards (true) or downwards curve
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}
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// Creates the curve mapping function.
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func (e Exponential) Make() utility.Curve {
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infl, exp := e.Infl, e.Exp
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if e.Convex {
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return func(x float64) float64 {
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return math.Pow(math.Abs(x-infl), exp)
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}
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} else {
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return func(x float64) float64 {
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return 1 - math.Pow(math.Abs(x-infl), exp)
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}
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}
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}
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