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operator_unary_negative.hpp
Go to the documentation of this file.
1 #ifndef STAN_MATH_REV_CORE_OPERATOR_UNARY_NEGATIVE_HPP
2 #define STAN_MATH_REV_CORE_OPERATOR_UNARY_NEGATIVE_HPP
3
4 #include <stan/math/rev/core/var.hpp>
5 #include <stan/math/rev/core/v_vari.hpp>
6 #include <boost/math/special_functions/fpclassify.hpp>
7 #include <limits>
8
9 namespace stan {
10 namespace math {
11
12 namespace {
13 class neg_vari : public op_v_vari {
14 public:
15 explicit neg_vari(vari* avi) :
16 op_v_vari(-(avi->val_), avi) {
17 }
18 void chain() {
19 if (unlikely(boost::math::isnan(avi_->val_)))
20 avi_->adj_ = std::numeric_limits<double>::quiet_NaN();
21 else
22 avi_->adj_ -= adj_;
23 }
24 };
25 }
26
51 inline var operator-(const var& a) {
52 return var(new neg_vari(a.vi_));
53 }
54
55 }
56 }
57 #endif
stan::math::operator-
fvar< T > operator-(const fvar< T > &x1, const fvar< T > &x2)
Definition: operator_subtraction.hpp:14
stan
Definition: log_sum_exp.hpp:8
stan::math::var
Independent (input) and dependent (output) variables for gradients.
Definition: var.hpp:31
boost::math::isnan
bool isnan(const stan::math::var &v)
Checks if the given number is NaN.
Definition: boost_isnan.hpp:22
unlikely
#define unlikely(x)
Definition: likely.hpp:9
v_vari.hpp
stan::math::var::vi_
vari * vi_
Pointer to the implementation of this variable.
Definition: var.hpp:43
var.hpp

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