// series near these points.
//
// ctan(z) = -i ctanh(iz).
//
// ACCURACY:
//
//                      Relative error:
// arithmetic   domain     # trials      peak         rms
//    DEC       -10,+10      5200       7.1e-17     1.6e-17
//    IEEE      -10,+10     30000       7.2e-16     1.2e-16
// Also tested by ctan * ccot = 1 and catan(ctan(z))  =  z.

// Tan returns the tangent of x.

//

// Atanh returns the inverse hyperbolic tangent of x.
//
// Special cases are:
//
//	Atanh(1) = +Inf
//	Atanh(±0) = ±0
//	Atanh(-1) = -Inf
//	Atanh(x) = NaN if x < -1 or x > 1
//	Atanh(NaN) = NaN
func Atanh(x float64) float64 {
	if haveArchAtanh {
		return archAtanh(x)
	}
	return atanh(x)
}

func atanh(x float64) float64 {
	const NearZero = 1.0 / (1 << 28) // 2**-28
	// special cases

	1.12811678491632931402e2,
	2.23548839060100448583e3,
	4.84406305325125486048e3,
}

// Tanh returns the hyperbolic tangent of x.
//
// Special cases are:
//
//	Tanh(±0) = ±0
//	Tanh(±Inf) = ±1
//	Tanh(NaN) = NaN
func Tanh(x float64) float64 {
	if haveArchTanh {
		return archTanh(x)
	}
	return tanh(x)
}

func tanh(x float64) float64 {
	const MAXLOG = 8.8029691931113054295988e+01 // log(2**127)
	z := Abs(x)

	t = imag(x) - 1
	b := x2 + t*t
	if b == 0 {
		return NaN()
	}
	t = imag(x) + 1
	c := (x2 + t*t) / b
	return complex(w, 0.25*math.Log(c))
}

// Atanh returns the inverse hyperbolic tangent of x.
func Atanh(x complex128) complex128 {
	z := complex(-imag(x), real(x)) // z = i * x
	z = Atan(z)
	return complex(imag(z), -real(z)) // z = -i * z

		}
	}
}
func TestAtanh(t *testing.T) {
	for i := 0; i < len(vc); i++ {
		if f := Atanh(vc[i]); !cVeryclose(atanh[i], f) {
			t.Errorf("Atanh(%g) = %g, want %g", vc[i], f, atanh[i])
		}
	}
	for _, v := range atanhSC {
		if f := Atanh(v.in); !cAlike(v.want, f) {
			t.Errorf("Atanh(%g) = %g, want %g", v.in, f, v.want)
		}
		if math.IsNaN(imag(v.in)) || math.IsNaN(imag(v.want)) {

package math

// Export internal functions and variable for testing.
var Log10NoVec = log10
var CosNoVec = cos
var CoshNoVec = cosh
var SinNoVec = sin
var SinhNoVec = sinh
var TanhNoVec = tanh
var Log1pNovec = log1p
var AtanhNovec = atanh
var AcosNovec = acos
var AcoshNovec = acosh
var AsinNovec = asin
var AsinhNovec = asinh
var ErfNovec = erf
var ErfcNovec = erfc
var AtanNovec = atan
var Atan2Novec = atan2

	}
	for i := 0; i < len(vf); i++ {
		a := vf[i] / 10
		if f := AtanhNovec(a); !veryclose(atanh[i], f) {
			t.Errorf("Atanh(%g) = %g, want %g", a, f, atanh[i])
		}
	}
	for i := 0; i < len(vfatanhSC); i++ {
		if f := AtanhNovec(vfatanhSC[i]); !alike(atanhSC[i], f) {
			t.Errorf("Atanh(%g) = %g, want %g", vfatanhSC[i], f, atanhSC[i])
		}
	}
}

func TestAcosNovec(t *testing.T) {
	if !HasVX {

        break;
      case COSH:
        y = Cosh(scope_, x);
        break;
      case TANH:
        y = Tanh(scope_, x);
        break;
      case ASINH:
        y = Asinh(scope_, x);
        break;
      case ACOSH:
        y = Acosh(scope_, x);
        break;
      case ATANH:
        y = Atanh(scope_, x);
        break;
      case SIGMOID:
        y = Sigmoid(scope_, x);
        break;

func ExampleAtan() {
	fmt.Printf("%.2f", math.Atan(0))
	// Output: 0.00
}

func ExampleAtan2() {
	fmt.Printf("%.2f", math.Atan2(0, 0))
	// Output: 0.00
}

func ExampleAtanh() {
	fmt.Printf("%.2f", math.Atanh(0))
	// Output: 0.00
}

func ExampleCopysign() {
	fmt.Printf("%.2f", math.Copysign(3.2, -1))
	// Output: -3.20
}

func ExampleCos() {
	fmt.Printf("%.2f", math.Cos(math.Pi/2))
	// Output: 0.00
}

}

func TestAtanh(t *testing.T) {
	for i := 0; i < len(vf); i++ {
		a := vf[i] / 10
		if f := Atanh(a); !veryclose(atanh[i], f) {
			t.Errorf("Atanh(%g) = %g, want %g", a, f, atanh[i])
		}
	}
	for i := 0; i < len(vfatanhSC); i++ {
		if f := Atanh(vfatanhSC[i]); !alike(atanhSC[i], f) {
			t.Errorf("Atanh(%g) = %g, want %g", vfatanhSC[i], f, atanhSC[i])
		}
	}
}

func TestAtan2(t *testing.T) {