// Method :
//	Based on
//	        acosh(x) = log [ x + sqrt(x*x-1) ]
//	we have
//	        acosh(x) := log(x)+ln2,	if x is large; else
//	        acosh(x) := log(2x-1/(sqrt(x*x-1)+x)) if x>2; else
//	        acosh(x) := log1p(t+sqrt(2.0*t+t*t)); where t=x-1.
//
// Special cases:
//	acosh(x) is NaN with signal if x<1.
//	acosh(NaN) is NaN without signal.
//

// Acosh returns the inverse hyperbolic cosine of x.
//

        break;
      case SINH:
        y = Sinh(scope_, x);
        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;

// license that can be found in the LICENSE file.

package math_test

import (
	"fmt"
	"math"
)

func ExampleAcos() {
	fmt.Printf("%.2f", math.Acos(1))
	// Output: 0.00
}

func ExampleAcosh() {
	fmt.Printf("%.2f", math.Acosh(1))
	// Output: 0.00
}

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

func ExampleAsinh() {
	fmt.Printf("%.2f", math.Asinh(0))

		a := 1 + Abs(vf[i])
		if f := Acosh(a); !veryclose(acosh[i], f) {
			t.Errorf("Acosh(%g) = %g, want %g", a, f, acosh[i])
		}
	}
	for i := 0; i < len(vfacoshSC); i++ {
		if f := Acosh(vfacoshSC[i]); !alike(acoshSC[i], f) {
			t.Errorf("Acosh(%g) = %g, want %g", vfacoshSC[i], f, acoshSC[i])
		}
	}
}

func TestAsin(t *testing.T) {
	for i := 0; i < len(vf); i++ {
		a := vf[i] / 10

                 std::vector<Output>* grad_outputs) {
  // y = acosh(x)
  // dy/dx = 1 / sinh(y)
  auto dydx = Reciprocal(scope, Sinh(scope, op.output(0)));
  // grad(x) = grad(y) * conj(dy/dx)
  grad_outputs->push_back(
      Mul(scope, grad_inputs[0], ConjugateHelper(scope, dydx)));
  return scope.status();
}
REGISTER_GRADIENT_OP("Acosh", AcoshGrad);

Status AtanhGrad(const Scope& scope, const Operation& op,

      new absl::flat_hash_map<string, std::vector<string>>{
          // Unary
          {"PW",
           {"ComplexAbs", "Angle", "Conj", "Abs", "Acos", "Acosh", "Asin",
            "Atan", "Atanh", "Ceil", "Cos", "Cosh", "Sin", "Exp", "Expm1",
            "Floor", "IsFinite", "IsInf", "IsNan", "Inv", "Reciprocal", "Log",
            "Log1p", "Invert", "LogicalNot", "Ndtri", "Neg", "Rint", "Round",

}

// Complex hyperbolic cosine
//
// DESCRIPTION:
//
// ccosh(z) = cosh x  cos y + i sinh x sin y .
//
// ACCURACY:
//
//                      Relative error:
// arithmetic   domain     # trials      peak         rms
//    IEEE      -10,+10     30000       2.9e-16     8.1e-17

// Cosh returns the hyperbolic cosine of x.
func Cosh(x complex128) complex128 {
	switch re, im := real(x), imag(x); {

	}

	if sign {
		temp = -temp
	}
	return temp
}

// Cosh returns the hyperbolic cosine of x.
//
// Special cases are:
//
//	Cosh(±0) = 1
//	Cosh(±Inf) = +Inf
//	Cosh(NaN) = NaN
func Cosh(x float64) float64 {
	if haveArchCosh {
		return archCosh(x)
	}
	return cosh(x)
}

func cosh(x float64) float64 {
	x = Abs(x)
	if x > 21 {
		return Exp(x) * 0.5
	}
	ex := Exp(x)

		temp = satan(x / temp)
	}

	if sign {
		temp = -temp
	}
	return temp
}

// Acos returns the arccosine, in radians, of x.
//
// Special case is:
//
//	Acos(x) = NaN if x < -1 or x > 1
func Acos(x float64) float64 {
	if haveArchAcos {
		return archAcos(x)
	}
	return acos(x)
}

func acos(x float64) float64 {
	return Pi/2 - Asin(x)

  %0, %1, %2 = "tf.IfRegion"(%arg0) ({
     %t0 = "tf.Abs"(%arg1) : (tensor<2xf32>) -> tensor<2xf32>
     %t1 = "tf.Acos"(%arg1) : (tensor<2xf32>) -> tensor<2xf32>
     %t2 = "tf.Acosh"(%arg1) : (tensor<2xf32>) -> tensor<2xf32>
    "tf.Yield"(%t0, %t1, %t2) : (tensor<2xf32>, tensor<2xf32>, tensor<2xf32>) -> ()
    }, {