1 #ifndef STAN_MATH_REV_SCAL_FUN_INV_SQRT_HPP
2 #define STAN_MATH_REV_SCAL_FUN_INV_SQRT_HPP
12 class inv_sqrt_vari :
public op_v_vari {
14 explicit inv_sqrt_vari(vari* avi) :
15 op_v_vari(stan::math::
inv_sqrt(avi->val_), avi) {
18 avi_->adj_ -= 0.5 * adj_ / (avi_->val_ *
std::sqrt(avi_->val_));
43 return var(
new inv_sqrt_vari(a.
vi_));
fvar< T > inv_sqrt(const fvar< T > &x)
fvar< T > sqrt(const fvar< T > &x)
Independent (input) and dependent (output) variables for gradients.
vari * vi_
Pointer to the implementation of this variable.