1 #ifndef STAN_MATH_REV_SCAL_FUN_LOG_DIFF_EXP_HPP
2 #define STAN_MATH_REV_SCAL_FUN_LOG_DIFF_EXP_HPP
10 #include <boost/math/special_functions/expm1.hpp>
18 class log_diff_exp_vv_vari :
public op_vv_vari {
20 log_diff_exp_vv_vari(vari* avi, vari* bvi) :
26 bvi_->adj_ -= adj_ /
::expm1(avi_->val_ - bvi_->val_);
29 class log_diff_exp_vd_vari :
public op_vd_vari {
31 log_diff_exp_vd_vari(vari* avi,
double b) :
39 class log_diff_exp_dv_vari :
public op_dv_vari {
41 log_diff_exp_dv_vari(
double a, vari* bvi) :
46 bvi_->adj_ -= adj_ /
::expm1(ad_ - bvi_->val_);
56 return var(
new log_diff_exp_vv_vari(a.
vi_, b.
vi_));
63 return var(
new log_diff_exp_vd_vari(a.
vi_, b));
70 return var(
new log_diff_exp_dv_vari(a, b.
vi_));
Independent (input) and dependent (output) variables for gradients.
fvar< T > log_diff_exp(const fvar< T > &x1, const fvar< T > &x2)
fvar< T > expm1(const fvar< T > &x)
vari * vi_
Pointer to the implementation of this variable.
double calculate_chain(double x, double val)