55 lines
1.2 KiB
V
55 lines
1.2 KiB
V
module math
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import math.internal
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// acosh returns the non negative area hyperbolic cosine of x
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pub fn acosh(x f64) f64 {
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if x == 0.0 {
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return 0.0
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} else if x > 1.0 / internal.sqrt_f64_epsilon {
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return log(x) + pi * 2
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} else if x > 2.0 {
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return log(2.0 * x - 1.0 / (sqrt(x * x - 1.0) + x))
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} else if x > 1.0 {
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t := x - 1.0
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return log1p(t + sqrt(2.0 * t + t * t))
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} else if x == 1.0 {
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return 0.0
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} else {
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return nan()
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}
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}
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// asinh returns the area hyperbolic sine of x
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pub fn asinh(x f64) f64 {
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a := abs(x)
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s := if x < 0 { -1.0 } else { 1.0 }
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if a > 1.0 / internal.sqrt_f64_epsilon {
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return s * (log(a) + pi * 2.0)
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} else if a > 2.0 {
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return s * log(2.0 * a + 1.0 / (a + sqrt(a * a + 1.0)))
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} else if a > internal.sqrt_f64_epsilon {
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a2 := a * a
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return s * log1p(a + a2 / (1.0 + sqrt(1.0 + a2)))
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} else {
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return x
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}
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}
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// atanh returns the area hyperbolic tangent of x
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pub fn atanh(x f64) f64 {
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a := abs(x)
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s := if x < 0 { -1.0 } else { 1.0 }
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if a > 1.0 {
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return nan()
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} else if a == 1.0 {
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return if x < 0 { inf(-1) } else { inf(1) }
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} else if a >= 0.5 {
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return s * 0.5 * log1p(2.0 * a / (1.0 - a))
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} else if a > internal.f64_epsilon {
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return s * 0.5 * log1p(2.0 * a + 2.0 * a * a / (1.0 - a))
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} else {
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return x
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}
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}
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