Stan Math Library  2.9.0
reverse mode automatic differentiation
abs.hpp
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1 #ifndef STAN_MATH_FWD_SCAL_FUN_ABS_HPP
2 #define STAN_MATH_FWD_SCAL_FUN_ABS_HPP
3 
5 #include <stan/math/fwd/core.hpp>
10 
11 namespace stan {
12  namespace math {
13 
14  template<typename T>
15  inline fvar<T> abs(const fvar<T>& x) {
16  using stan::math::abs;
18  if (x.val_ > 0.0)
19  return x;
20  else if (x.val_ < 0.0)
21  return fvar<T>(-x.val_, -x.d_);
22  else if (x.val_ == 0.0)
23  return fvar<T>(0, 0);
24  else
26  }
27 
28  }
29 }
30 #endif
fvar< T > abs(const fvar< T > &x)
Definition: abs.hpp:15
const double NOT_A_NUMBER
(Quiet) not-a-number value.
Definition: constants.hpp:56
T value_of(const fvar< T > &v)
Return the value of the specified variable.
Definition: value_of.hpp:16

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