1 #ifndef STAN__PROB__DISTRIBUTIONS__UNIVARIATE__CONTINUOUS__PARETO_TYPE_2_HPP
2 #define STAN__PROB__DISTRIBUTIONS__UNIVARIATE__CONTINUOUS__PARETO_TYPE_2_HPP
4 #include <boost/random/variate_generator.hpp>
21 template <
bool propto,
22 typename T_y,
typename T_loc,
typename T_scale,
typename T_shape>
23 typename return_type<T_y,T_loc,T_scale,T_shape>::type
25 const T_shape& alpha) {
26 static const char*
function =
"stan::prob::pareto_type_2_log(%1%)";
54 "Random variable",
"Scale parameter",
66 size_t N =
max_size(y, mu, lambda, alpha);
70 operands_and_partials(y, mu, lambda, alpha);
75 for (
size_t n = 0; n < N; n++)
83 for (
size_t n = 0; n <
length(lambda); n++)
89 for (
size_t n = 0; n <
length(alpha); n++)
95 for (
size_t n = 0; n <
length(alpha); n++)
96 inv_alpha[n] = 1 /
value_of(alpha_vec[n]);
98 for (
size_t n = 0; n < N; n++) {
99 const double y_dbl =
value_of(y_vec[n]);
100 const double mu_dbl =
value_of(mu_vec[n]);
101 const double lambda_dbl =
value_of(lambda_vec[n]);
102 const double alpha_dbl =
value_of(alpha_vec[n]);
103 const double sum_dbl = lambda_dbl + y_dbl + mu_dbl;
104 const double inv_sum = 1.0 / sum_dbl;
105 const double alpha_div_sum = alpha_dbl / sum_dbl;
106 const double deriv_1_2 = inv_sum + alpha_div_sum;
110 logp += log_alpha[n];
112 logp -= log_lambda[n];
114 logp -= (alpha_dbl + 1.0) * log1p_scaled_diff[n];
118 operands_and_partials.
d_x1[n] -= deriv_1_2;
120 operands_and_partials.
d_x2[n] += deriv_1_2;
122 operands_and_partials.
d_x3[n] -= alpha_div_sum * (mu_dbl - y_dbl)
123 / lambda_dbl + inv_sum;
125 operands_and_partials.
d_x4[n] += inv_alpha[n] - log1p_scaled_diff[n];
127 return operands_and_partials.
to_var(logp);
130 template <
typename T_y,
typename T_loc,
typename T_scale,
typename T_shape>
134 const T_scale& lambda,
const T_shape& alpha) {
135 return pareto_type_2_log<false>(y,mu,lambda,alpha);
138 template <
typename T_y,
typename T_loc,
typename T_scale,
typename T_shape>
141 const T_scale& lambda,
const T_shape& alpha) {
152 static const char*
function =
"stan::prob::pareto_type_2_cdf(%1%)";
171 "Random variable",
"Scale parameter",
172 "Shape parameter", &P);
179 size_t N =
max_size(y, mu, lambda, alpha);
182 operands_and_partials(y, mu, lambda, alpha);
206 for (
size_t i = 0; i < N; i++) {
207 const double lambda_dbl =
value_of(lambda_vec[i]);
208 const double alpha_dbl =
value_of(alpha_vec[i]);
209 const double temp = 1 + (
value_of(y_vec[i])
212 p1_pow_alpha[i] =
pow(temp, -alpha_dbl);
217 grad_1_2[i] = p1_pow_alpha[i] / temp * alpha_dbl / lambda_dbl;
220 grad_3[i] =
log(temp) * p1_pow_alpha[i];
225 for (
size_t n = 0; n < N; n++) {
228 const double y_dbl =
value_of(y_vec[n]);
229 const double mu_dbl =
value_of(mu_vec[n]);
230 const double lambda_dbl =
value_of(lambda_vec[n]);
232 const double Pn = 1.0 - p1_pow_alpha[n];
238 operands_and_partials.
d_x1[n] += grad_1_2[n] / Pn;
240 operands_and_partials.
d_x2[n] -= grad_1_2[n] / Pn;
242 operands_and_partials.
d_x3[n] += (mu_dbl - y_dbl)
243 * grad_1_2[n] / lambda_dbl / Pn;
245 operands_and_partials.
d_x4[n] += grad_3[n] / Pn;
250 operands_and_partials.
d_x1[n] *= P;
254 operands_and_partials.
d_x2[n] *= P;
258 operands_and_partials.
d_x3[n] *= P;
262 operands_and_partials.
d_x4[n] *= P;
265 return operands_and_partials.
to_var(P);
268 template <
typename T_y,
typename T_loc,
typename T_scale,
typename T_shape>
271 const T_scale& lambda,
const T_shape& alpha) {
282 static const char*
function =
"stan::prob::pareto_type_2_cdf_log(%1%)";
302 "Random variable",
"Scale parameter",
303 "Shape parameter", &P);
310 size_t N =
max_size(y, mu, lambda, alpha);
313 operands_and_partials(y, mu, lambda, alpha);
327 inv_p1_pow_alpha_minus_one(N);
334 log_1p_y_over_lambda(N);
336 for (
size_t i = 0; i < N; i++) {
337 const double temp = 1.0 + (
value_of(y_vec[i])
340 const double p1_pow_alpha =
pow(temp,
value_of(alpha_vec[i]));
341 cdf_log[i] =
log1m(1.0 / p1_pow_alpha);
343 inv_p1_pow_alpha_minus_one[i] = 1.0 / (p1_pow_alpha - 1.0);
346 log_1p_y_over_lambda[i] =
log(temp);
351 for (
size_t n = 0; n < N; n++) {
353 const double y_dbl =
value_of(y_vec[n]);
354 const double mu_dbl =
value_of(mu_vec[n]);
355 const double lambda_dbl =
value_of(lambda_vec[n]);
356 const double alpha_dbl =
value_of(alpha_vec[n]);
358 const double grad_1_2 = alpha_dbl
359 * inv_p1_pow_alpha_minus_one[n] / (lambda_dbl - mu_dbl + y_dbl);
365 operands_and_partials.
d_x1[n] += grad_1_2;
367 operands_and_partials.
d_x2[n] -= grad_1_2;
369 operands_and_partials.
d_x3[n] += (mu_dbl - y_dbl) * grad_1_2
372 operands_and_partials.
d_x4[n] += log_1p_y_over_lambda[n]
373 * inv_p1_pow_alpha_minus_one[n];
376 return operands_and_partials.
to_var(P);
379 template <
typename T_y,
typename T_loc,
typename T_scale,
typename T_shape>
382 const T_scale& lambda,
const T_shape& alpha) {
393 static const char*
function =
"stan::prob::pareto_type_2_ccdf_log(%1%)";
411 "Random variable",
"Scale parameter",
412 "Shape parameter", &P);
419 size_t N =
max_size(y, mu, lambda, alpha);
422 operands_and_partials(y, mu, lambda, alpha);
439 a_over_lambda_plus_y(N);
446 log_1p_y_over_lambda(N);
448 for (
size_t i = 0; i < N; i++) {
449 const double y_dbl =
value_of(y_vec[i]);
450 const double mu_dbl =
value_of(mu_vec[i]);
451 const double lambda_dbl =
value_of(lambda_vec[i]);
452 const double alpha_dbl =
value_of(alpha_vec[i]);
453 const double temp = 1.0 + (y_dbl - mu_dbl) / lambda_dbl;
454 const double log_temp =
log(temp);
456 ccdf_log[i] = -alpha_dbl * log_temp;
462 a_over_lambda_plus_y[i] = alpha_dbl / (y_dbl - mu_dbl + lambda_dbl);
465 log_1p_y_over_lambda[i] = log_temp;
470 for (
size_t n = 0; n < N; n++) {
472 const double y_dbl =
value_of(y_vec[n]);
473 const double mu_dbl =
value_of(mu_vec[n]);
474 const double lambda_dbl =
value_of(lambda_vec[n]);
480 operands_and_partials.
d_x1[n] -= a_over_lambda_plus_y[n];
482 operands_and_partials.
d_x2[n] += a_over_lambda_plus_y[n];
484 operands_and_partials.
d_x3[n] += a_over_lambda_plus_y[n]
485 * (y_dbl - mu_dbl) / lambda_dbl;
487 operands_and_partials.
d_x4[n] -= log_1p_y_over_lambda[n];
490 return operands_and_partials.
to_var(P);
499 static const char*
function =
"stan::prob::pareto_type_2_rng(%1%)";
507 return (
std::pow(1.0 - uniform_01, -1.0 / alpha) - 1.0) * lambda + mu;
fvar< T > log1m(const fvar< T > &x)
return_type< T_y, T_loc, T_scale, T_shape >::type pareto_type_2_ccdf_log(const T_y &y, const T_loc &mu, const T_scale &lambda, const T_shape &alpha)
T_return_type to_var(double logp)
bool check_positive_finite(const char *function, const T_y &y, const char *name, T_result *result)
fvar< T > pow(const fvar< T > &x1, const fvar< T > &x2)
double pareto_type_2_rng(const double mu, const double lambda, const double alpha, RNG &rng)
return_type< T_y, T_loc, T_scale, T_shape >::type pareto_type_2_cdf_log(const T_y &y, const T_loc &mu, const T_scale &lambda, const T_shape &alpha)
return_type< T_y, T_loc, T_scale, T_shape >::type pareto_type_2_cdf(const T_y &y, const T_loc &mu, const T_scale &lambda, const T_shape &alpha)
DoubleVectorView allocates double values to be used as intermediate values.
bool check_finite(const char *function, const T_y &y, const char *name, T_result *result)
Checks if the variable y is finite.
T value_of(const fvar< T > &v)
Return the value of the specified variable.
A variable implementation that stores operands and derivatives with respect to the variable...
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...
double value_of(const T x)
Return the value of the specified scalar argument converted to a double value.
Template metaprogram to calculate whether a summand needs to be included in a proportional (log) prob...
VectorView< double *, is_vector< T2 >::value, is_constant_struct< T2 >::value > d_x2
double uniform_rng(const double alpha, const double beta, RNG &rng)
bool check_nonnegative(const char *function, const T_y &y, const char *name, T_result *result)
bool check_consistent_sizes(const char *function, const T1 &x1, const T2 &x2, const char *name1, const char *name2, T_result *result)
size_t max_size(const T1 &x1, const T2 &x2)
bool check_positive(const char *function, const T_y &y, const char *name, T_result *result)
bool check_not_nan(const char *function, const T_y &y, const char *name, T_result *result)
Checks if the variable y is nan.
VectorView< double *, is_vector< T4 >::value, is_constant_struct< T4 >::value > d_x4
return_type< T_y, T_loc, T_scale, T_shape >::type pareto_type_2_log(const T_y &y, const T_loc &mu, const T_scale &lambda, const T_shape &alpha)
VectorView< double *, is_vector< T1 >::value, is_constant_struct< T1 >::value > d_x1
VectorView< double *, is_vector< T3 >::value, is_constant_struct< T3 >::value > d_x3
fvar< T > log(const fvar< T > &x)
VectorView is a template metaprogram that takes its argument and allows it to be used like a vector...
bool check_greater_or_equal(const char *function, const T_y &y, const T_low &low, const char *name, T_result *result)
fvar< T > log1p(const fvar< T > &x)
boost::math::tools::promote_args< T >::type log1m(T x)
Return the natural logarithm of one minus the specified value.