mirror of
https://github.com/make-42/xyosc
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41 lines
742 B
Go
41 lines
742 B
Go
package math32
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func Sinh(x float32) float32 {
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// The coefficients are #2029 from Hart & Cheney. (20.36D)
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const (
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P0 = -0.6307673640497716991184787251e+6
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P1 = -0.8991272022039509355398013511e+5
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P2 = -0.2894211355989563807284660366e+4
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P3 = -0.2630563213397497062819489e+2
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Q0 = -0.6307673640497716991212077277e+6
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Q1 = 0.1521517378790019070696485176e+5
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Q2 = -0.173678953558233699533450911e+3
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)
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sign := false
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if x < 0 {
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x = -x
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sign = true
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}
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var temp float32
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switch {
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case x > 21:
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temp = Exp(x) * 0.5
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case x > 0.5:
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ex := Exp(x)
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temp = (ex - 1/ex) * 0.5
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default:
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sq := x * x
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temp = (((P3*sq+P2)*sq+P1)*sq + P0) * x
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temp = temp / (((sq+Q2)*sq+Q1)*sq + Q0)
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}
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if sign {
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temp = -temp
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}
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return temp
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}
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