1 #ifndef STAN_MATH_REV_SCAL_FUN_LOG_MIX_HPP 2 #define STAN_MATH_REV_SCAL_FUN_LOG_MIX_HPP 30 double& one_m_exp_lam2_m_lam1,
31 double& one_m_t_prod_exp_lam2_m_lam1,
32 double& one_d_t_plus_one_m_t_prod_exp_lam2_m_lam1) {
34 double lam2_m_lam1 = lambda2_val - lambda1_val;
35 double exp_lam2_m_lam1 =
exp(lam2_m_lam1);
36 one_m_exp_lam2_m_lam1 = 1 - exp_lam2_m_lam1;
37 double one_m_t = 1 - theta_val;
38 one_m_t_prod_exp_lam2_m_lam1 = one_m_t * exp_lam2_m_lam1;
39 one_d_t_plus_one_m_t_prod_exp_lam2_m_lam1
40 = 1 / (theta_val + one_m_t_prod_exp_lam2_m_lam1);
82 template <
typename T_theta,
88 const T_lambda1& lambda1,
89 const T_lambda2& lambda2) {
94 operands_and_partials(theta, lambda1, lambda2);
96 double theta_double =
value_of(theta);
97 const double lambda1_double =
value_of(lambda1);
98 const double lambda2_double =
value_of(lambda2);
100 double log_mix_function_value
101 =
log_mix(theta_double, lambda1_double, lambda2_double);
103 double one_m_exp_lam2_m_lam1(0.0);
104 double one_m_t_prod_exp_lam2_m_lam1(0.0);
105 double one_d_t_plus_one_m_t_prod_exp_lam2_m_lam1(0.0);
107 if (lambda1 > lambda2) {
111 one_m_exp_lam2_m_lam1,
112 one_m_t_prod_exp_lam2_m_lam1,
113 one_d_t_plus_one_m_t_prod_exp_lam2_m_lam1);
118 one_m_exp_lam2_m_lam1,
119 one_m_t_prod_exp_lam2_m_lam1,
120 one_d_t_plus_one_m_t_prod_exp_lam2_m_lam1);
121 one_m_exp_lam2_m_lam1 = -one_m_exp_lam2_m_lam1;
122 theta_double = one_m_t_prod_exp_lam2_m_lam1;
123 one_m_t_prod_exp_lam2_m_lam1 = 1.0 -
value_of(theta);
127 operands_and_partials.
d_x1[0]
128 = one_m_exp_lam2_m_lam1
129 * one_d_t_plus_one_m_t_prod_exp_lam2_m_lam1;
131 operands_and_partials.
d_x2[0]
133 * one_d_t_plus_one_m_t_prod_exp_lam2_m_lam1;
135 operands_and_partials.
d_x3[0]
136 = one_m_t_prod_exp_lam2_m_lam1
137 * one_d_t_plus_one_m_t_prod_exp_lam2_m_lam1;
139 return operands_and_partials.
value(log_mix_function_value);
VectorView< T_return_type, false, true > d_x2
T value_of(const fvar< T > &v)
Return the value of the specified variable.
fvar< T > log(const fvar< T > &x)
T_return_type value(double value)
Returns a T_return_type with the value specified with the partial derivatves.
boost::math::tools::promote_args< typename scalar_type< T1 >::type, typename scalar_type< T2 >::type, typename scalar_type< T3 >::type, typename scalar_type< T4 >::type, typename scalar_type< T5 >::type, typename scalar_type< T6 >::type >::type type
Metaprogram to determine if a type has a base scalar type that can be assigned to type double...
fvar< T > exp(const fvar< T > &x)
This class builds partial derivatives with respect to a set of operands.
VectorView< T_return_type, false, true > d_x3
void log_mix_partial_helper(const T_theta &theta, const T_lambda1 &lambda1, const T_lambda2 &lambda2, typename boost::math::tools::promote_args< T_theta, T_lambda1, T_lambda2 >::type(&partials_array)[N])
fvar< T > log_mix(const fvar< T > &theta, const fvar< T > &lambda1, const fvar< T > &lambda2)
Return the log mixture density with specified mixing proportion and log densities and its derivative ...
VectorView< T_return_type, false, true > d_x1