log1m

Author: andrjohns

stan/math/opencl/prim/pareto_lcdf.hpp

@@ -68,7 +68,8 @@ return_type_t<T_y_cl, T_scale_cl, T_shape_cl> pareto_lcdf(
 
   auto log_quot = log(elt_divide(y_min_val, y_val));
   auto exp_prod = exp(elt_multiply(alpha_val, log_quot));
-  auto lcdf_expr = colwise_sum(log(1.0 - exp_prod));
+  // TODO(Andrew) Further simplify derivatives and log1m_exp below
+  auto lcdf_expr = colwise_sum(log1m(exp_prod));
 
   auto common_deriv = elt_divide(exp_prod, 1.0 - exp_prod);
 

stan/math/opencl/prim/weibull_lcdf.hpp

@@ -65,7 +65,8 @@ return_type_t<T_y_cl, T_shape_cl, T_scale_cl> weibull_lcdf(
 
   auto pow_n = pow(elt_divide(y_val, sigma_val), alpha_val);
   auto exp_n = exp(-pow_n);
-  auto lcdf_expr = colwise_sum(log(1.0 - exp_n));
+  // TODO(Andrew) Further simplify derivatives and log1m_exp below
+  auto lcdf_expr = colwise_sum(log1m(exp_n));
 
   auto rep_deriv = elt_divide(pow_n, elt_divide(1.0, exp_n) - 1.0);
   auto deriv_y_sigma = elt_multiply(rep_deriv, alpha_val);

stan/math/prim/fun/inc_beta_ddb.hpp

@@ -7,7 +7,7 @@
 #include <stan/math/prim/fun/inc_beta.hpp>
 #include <stan/math/prim/fun/inc_beta_dda.hpp>
 #include <stan/math/prim/fun/inv.hpp>
-#include <stan/math/prim/fun/log.hpp>
+#include <stan/math/prim/fun/log1m.hpp>
 #include <cmath>
 
 namespace stan {
@@ -87,7 +87,7 @@ T inc_beta_ddb(T a, T b, T z, T digamma_b, T digamma_ab) {
     }
   }
 
-  return inc_beta(a, b, z) * (log(1 - z) - digamma_b + sum_numer / sum_denom);
+  return inc_beta(a, b, z) * (log1m(z) - digamma_b + sum_numer / sum_denom);
 }
 
 }  // namespace math

stan/math/prim/fun/inc_beta_ddz.hpp

@@ -5,6 +5,7 @@
 #include <stan/math/prim/fun/exp.hpp>
 #include <stan/math/prim/fun/lgamma.hpp>
 #include <stan/math/prim/fun/log.hpp>
+#include <stan/math/prim/fun/log1m.hpp>
 #include <boost/math/special_functions/beta.hpp>
 #include <cmath>
 
@@ -29,7 +30,7 @@ template <typename T>
 T inc_beta_ddz(T a, T b, T z) {
   using std::exp;
   using std::log;
-  return exp((b - 1) * log(1 - z) + (a - 1) * log(z) + lgamma(a + b) - lgamma(a)
+  return exp((b - 1) * log1m(z) + (a - 1) * log(z) + lgamma(a + b) - lgamma(a)
              - lgamma(b));
 }
 

stan/math/prim/prob/pareto_lcdf.hpp

@@ -69,7 +69,8 @@ return_type_t<T_y, T_scale, T_shape> pareto_lcdf(const T_y& y,
   const auto& exp_prod
       = to_ref_if<!is_constant_all<T_y, T_scale, T_shape>::value>(
           exp(alpha_val * log_quot));
-  T_partials_return P = sum(log(1 - exp_prod));
+  // TODO(Andrew) Further simplify derivatives and log1m_exp below
+  T_partials_return P = sum(log1m(exp_prod));
 
   if (!is_constant_all<T_y, T_scale, T_shape>::value) {
     const auto& common_deriv = to_ref_if<(!is_constant_all<T_y, T_scale>::value

stan/math/prim/prob/skew_double_exponential_lccdf.hpp

@@ -109,7 +109,7 @@ return_type_t<T_y, T_loc, T_scale, T_skewness> skew_double_exponential_lccdf(
     if (y_dbl <= mu_dbl) {
       cdf_log += log1m(tau_dbl * exp(-2.0 * expo));
     } else {
-      cdf_log += log(1 - tau_dbl) - 2.0 * expo;
+      cdf_log += log1m(tau_dbl) - 2.0 * expo;
     }
 
     if (!is_constant_all<T_y>::value) {

stan/math/prim/prob/weibull_lcdf.hpp

@@ -8,6 +8,7 @@
 #include <stan/math/prim/fun/as_value_column_array_or_scalar.hpp>
 #include <stan/math/prim/fun/exp.hpp>
 #include <stan/math/prim/fun/log.hpp>
+#include <stan/math/prim/fun/log1m.hpp>
 #include <stan/math/prim/fun/size_zero.hpp>
 #include <stan/math/prim/fun/max_size.hpp>
 #include <stan/math/prim/fun/to_ref.hpp>
@@ -67,7 +68,8 @@ return_type_t<T_y, T_shape, T_scale> weibull_lcdf(const T_y& y,
   const auto& pow_n = to_ref_if<any_derivs>(pow(y_val / sigma_val, alpha_val));
   const auto& exp_n = to_ref_if<any_derivs>(exp(-pow_n));
 
-  T_partials_return cdf_log = sum(log(1 - exp_n));
+  // TODO(Andrew) Further simplify derivatives and log1m_exp below
+  T_partials_return cdf_log = sum(log1m(exp_n));
 
   if (!is_constant_all<T_y, T_scale, T_shape>::value) {
     const auto& rep_deriv = to_ref_if<(!is_constant_all<T_y, T_scale>::value