* R*R)} of the population standard deviation of {@code y}, where {@code R} is the Pearson's
   * correlation coefficient (as given by {@link #pearsonsCorrelationCoefficient()}).
   *
   * <p>The corresponding root-mean-square error in {@code x} as a function of {@code y} is a
   * fraction {@code sqrt(1/(R*R) - 1)} of the population standard deviation of {@code x}. This fit

//   ******@****.***

// Complex natural logarithm
//
// DESCRIPTION:
//
// Returns complex logarithm to the base e (2.718...) of
// the complex argument z.
//
// If
//       z = x + iy, r = sqrt( x**2 + y**2 ),
// then
//       w = log(r) + i arctan(y/x).
//
// The arctangent ranges from -PI to +PI.
//
// ACCURACY:
//
//                      Relative error:

   * R*R)} of the population standard deviation of {@code y}, where {@code R} is the Pearson's
   * correlation coefficient (as given by {@link #pearsonsCorrelationCoefficient()}).
   *
   * <p>The corresponding root-mean-square error in {@code x} as a function of {@code y} is a
   * fraction {@code sqrt(1/(R*R) - 1)} of the population standard deviation of {@code x}. This fit

}

Status SqrtModel(AbstractContext* ctx,
                 absl::Span<AbstractTensorHandle* const> inputs,
                 absl::Span<AbstractTensorHandle*> outputs) {
  return ops::Sqrt(ctx, inputs[0], &outputs[0], "Sqrt");
}

Status NegModel(AbstractContext* ctx,
                absl::Span<AbstractTensorHandle* const> inputs,
                absl::Span<AbstractTensorHandle*> outputs) {

// ComplexAbs is a helper type that defines an Abs method for
// complex types.
type ComplexAbs[T Complex] T

func (a ComplexAbs[T]) Abs() ComplexAbs[T] {
	r := float64(real(a))
	i := float64(imag(a))
	d := math.Sqrt(r * r + i * i)
	return ComplexAbs[T](complex(d, 0))
}

func OrderedAbsDifference[T OrderedNumeric](a, b T) T {
	return T(AbsDifference(OrderedAbs[T](a), OrderedAbs[T](b)))
}

                const std::vector<Output>& grad_inputs,
                std::vector<Output>* grad_outputs) {
  // y = asin(x)
  // dy/dx = 1 / sqrt(1 - x^2)
  auto x2 = Square(scope, op.input(0));
  auto one = Cast(scope, Const(scope, 1.0), op.input(0).type());
  auto dydx = Reciprocal(scope, Sqrt(scope, Sub(scope, one, x2)));
  // grad(x) = grad(y) * conj(dy/dx)
  auto dx = Mul(scope, grad_inputs[0], ConjugateHelper(scope, dydx));

}

func TestDecimalConstants(t *testing.T) {
	sqrtM1String := "19681161376707505956807079304988542015446066515923890162744021073123829784752"
	if exp := new(Element).fromDecimal(sqrtM1String); sqrtM1.Equal(exp) != 1 {
		t.Errorf("sqrtM1 is %v, expected %v", sqrtM1, exp)
	}
	// d is in the parent package, and we don't want to expose d or fromDecimal.
	// dString := "37095705934669439343138083508754565189542113879843219016388785533085940283555"

// // complex types.
// type complexAbs[T Complex] T
//
// func (a complexAbs[T]) Abs() complexAbs[T] {
// 	r := float64(real(a))
// 	i := float64(imag(a))
// 	d := math.Sqrt(r*r + i*i)
// 	return complexAbs[T](complex(d, 0))
// }
//
// // OrderedAbsDifference returns the absolute value of the difference
// // between a and b, where a and b are of an ordered type.

	}
}

func TestSqrt(t *testing.T) {
	for i := 0; i < len(vf); i++ {
		a := Abs(vf[i])
		if f := SqrtGo(a); sqrt[i] != f {
			t.Errorf("SqrtGo(%g) = %g, want %g", a, f, sqrt[i])
		}
		a = Abs(vf[i])
		if f := Sqrt(a); sqrt[i] != f {
			t.Errorf("Sqrt(%g) = %g, want %g", a, f, sqrt[i])
		}
	}
	for i := 0; i < len(vfsqrtSC); i++ {
		if f := SqrtGo(vfsqrtSC[i]); !alike(sqrtSC[i], f) {

// ComplexAbs is a helper type that defines an Abs method for
// complex types.
type ComplexAbs[T Complex] T

func (a ComplexAbs[T]) Abs() ComplexAbs[T] {
	r := float64(real(a))
	i := float64(imag(a))
	d := math.Sqrt(r * r + i * i)
	return ComplexAbs[T](complex(d, 0))
}

func OrderedAbsDifference[T OrderedNumeric](a, b T) T {
	return T(AbsDifference(OrderedAbs[T](a), OrderedAbs[T](b)))
}