Refactor trend init update code.

src/HealthGPS/static_linear_model.cpp

@@ -130,15 +130,18 @@ void StaticLinearModel::initialise_factors(RuntimeContext &context, Person &pers
         // Initialise residual.
         auto residual_name = core::Identifier{names_[i].to_string() + "_residual"};
         double residual = residuals[i];
+
+        // Save residual.
         person.risk_factors[residual_name] = residual;
 
         // Initialise risk factor.
         double expected = get_expected(context, person.gender, person.age, names_[i], ranges_[i]);
         double factor = linear[i] + residual * stddev_[i];
         factor = expected * inverse_box_cox(factor, lambda_[i]);
+        factor = ranges_[i].clamp(factor);
 
-        // Save clamped risk factor.
-        person.risk_factors[names_[i]] = ranges_[i].clamp(factor);
+        // Save risk factor.
+        person.risk_factors[names_[i]] = factor;
     }
 }
 
@@ -159,15 +162,18 @@ void StaticLinearModel::update_factors(RuntimeContext &context, Person &person,
         double residual_old = person.risk_factors.at(residual_name);
         double residual = residuals[i] * info_speed_;
         residual += sqrt(1.0 - info_speed_ * info_speed_) * residual_old;
+
+        // Save residual.
         person.risk_factors.at(residual_name) = residual;
 
         // Update risk factor.
         double expected = get_expected(context, person.gender, person.age, names_[i], ranges_[i]);
         double factor = linear[i] + residual * stddev_[i];
         factor = expected * inverse_box_cox(factor, lambda_[i]);
+        factor = ranges_[i].clamp(factor);
 
-        // Save clamped risk factor.
-        person.risk_factors.at(names_[i]) = ranges_[i].clamp(factor);
+        // Save risk factor.
+        person.risk_factors.at(names_[i]) = factor;
     }
 }
 
@@ -176,24 +182,19 @@ void StaticLinearModel::initialise_trends(RuntimeContext &context, Person &perso
     // Approximate trends with linear models.
     auto linear = compute_linear_models(person, *trend_models_);
 
-    // Get elapsed time (years).
-    int elapsed_time = context.time_now() - context.start_time();
-
     // Initialise and apply trends (do not exist yet).
     for (size_t i = 0; i < names_.size(); i++) {
 
         // Initialise trend.
         auto trend_name = core::Identifier{names_[i].to_string() + "_trend"};
         double trend = (*trend_ranges_)[i].clamp(linear[i]);
-        person.risk_factors[trend_name] = trend;
 
-        // Apply trend to risk factor.
-        double factor = person.risk_factors.at(names_[i]);
-        factor *= pow(trend, elapsed_time);
-
-        // Save clamped risk factor.
-        person.risk_factors.at(names_[i]) = ranges_[i].clamp(factor);
+        // Save trend.
+        person.risk_factors[trend_name] = trend;
     }
+
+    // Apply trends.
+    update_trends(context, person);
 }
 
 void StaticLinearModel::update_trends(RuntimeContext &context, Person &person) const {
@@ -211,9 +212,10 @@ void StaticLinearModel::update_trends(RuntimeContext &context, Person &person) c
         // Apply trend to risk factor.
         double factor = person.risk_factors.at(names_[i]);
         factor *= pow(trend, elapsed_time);
+        factor = ranges_[i].clamp(factor);
 
-        // Save clamped risk factor.
-        person.risk_factors.at(names_[i]) = ranges_[i].clamp(factor);
+        // Save risk factor.
+        person.risk_factors.at(names_[i]) = factor;
     }
 }
 
@@ -258,9 +260,10 @@ void StaticLinearModel::update_policies(Person &person, bool intervene) const {
         // Compute policy.
         auto policy_name = core::Identifier{names_[i].to_string() + "_policy"};
         double policy = linear[i] + residual;
+        policy = policy_ranges_[i].clamp(policy);
 
-        // Save clamped policy.
-        person.risk_factors[policy_name] = policy_ranges_[i].clamp(policy);
+        // Save policy.
+        person.risk_factors[policy_name] = policy;
     }
 }
 
@@ -281,9 +284,10 @@ void StaticLinearModel::apply_policies(Person &person, bool intervene) const {
         // Apply policy to risk factor.
         double factor_old = person.risk_factors.at(names_[i]);
         double factor = factor_old * (1.0 + policy / 100.0);
+        factor = ranges_[i].clamp(factor);
 
-        // Save clamped risk factor.
-        person.risk_factors.at(names_[i]) = ranges_[i].clamp(factor);
+        // Save risk factor.
+        person.risk_factors.at(names_[i]) = factor;
     }
 }