1 #ifndef STAN_MATH_REV_CORE_STD_ISNAN_HPP
2 #define STAN_MATH_REV_CORE_STD_ISNAN_HPP
Independent (input) and dependent (output) variables for gradients.
int isnan(const stan::math::var &a)
Checks if the given number is NaN.
double val() const
Return the value of this variable.