It works!

src/factor_graph.rs

@@ -23,7 +23,7 @@ impl VariableArena {
         let index = self.variables.len();
 
         self.variables.push(Variable {
-            value: Gaussian::from_precision(0.0, 0.0),
+            value: Gaussian::from_pi_tau(0.0, 0.0),
             factors: HashMap::new(),
         });
 
@@ -46,26 +46,19 @@ pub struct Variable {
 
 impl Variable {
     pub fn attach_factor(&mut self, factor: usize) {
-        self.factors.insert(factor, Gaussian::from_precision(0.0, 0.0));
+        self.factors.insert(factor, Gaussian::from_pi_tau(0.0, 0.0));
     }
 
     pub fn update_value(&mut self, factor: usize, value: Gaussian) {
         let old = self.factors[&factor];
 
         let intermediate = value * old;
-        let new = intermediate / self.value;
+        self.factors.insert(factor, intermediate / self.value);
 
-        /*
-        println!("update_value: old={}, value={:?}, new={:?}, self.value={:?}",
-                 render_g(old),
-                 value,
-                 new,
-                 self.value);
-        */
-        self.value = new;
+        self.value = value;
     }
 
-    pub fn get_value(&self) -> Gaussian {
+     pub fn get_value(&self) -> Gaussian {
         self.value
     }
 
@@ -77,8 +70,6 @@ impl Variable {
 
         self.value = value;
 
-        println!("update_message: old={:?} msg={:?}, new={:?}", old, message, value);
-
         self.factors.insert(factor, message);
     }
 
@@ -110,8 +101,6 @@ impl PriorFactor {
     }
 
     pub fn start(&self, variable_arena: &mut VariableArena) {
-        println!("PriorFactor: variable.id={}, msg={:?}", self.variable.index, self.gaussian);
-
         variable_arena.get_mut(self.variable).unwrap().update_value(self.id, self.gaussian);
     }
 }
@@ -153,11 +142,9 @@ impl LikelihoodFactor {
             .map(|variable| variable.get_message(self.id))
             .unwrap();
 
-        let a = 1.0 / (1.0 + self.variance * (x.precision_mean() - fx.precision_mean()));
+        let a = 1.0 / (1.0 + self.variance * (x.pi() - fx.pi()));
 
-        let gaussian = Gaussian::from_precision(a * (x.precision_mean() - fx.precision_mean()), a * (x.precision() - fx.precision()));
-
-        println!("LikelihoodFactor: mean.id={}, msg={:?}", self.mean.index, gaussian);
+        let gaussian = Gaussian::from_pi_tau(a * (x.pi() - fx.pi()), a * (x.tau() - fx.tau()));
 
         variable_arena.get_mut(self.mean).unwrap().update_message(self.id, gaussian);
     }
@@ -173,12 +160,9 @@ impl LikelihoodFactor {
             .map(|variable| variable.get_message(self.id))
             .unwrap();
 
-        let a = 1.0 / (1.0 + self.variance * (y.precision_mean() - fy.precision_mean()));
+        let a = 1.0 / (1.0 + self.variance * (y.pi() - fy.pi()));
 
-        let gaussian = Gaussian::from_precision(a * (y.precision_mean() - fy.precision_mean()), a * (y.precision() - fy.precision()));
-
-
-        println!("LikelihoodFactor: value.id={}, msg={:?}", self.value.index, gaussian);
+        let gaussian = Gaussian::from_pi_tau(a * (y.pi() - fy.pi()), a * (y.tau() - fy.tau()));
 
         variable_arena.get_mut(self.value).unwrap().update_message(self.id, gaussian);
     }
@@ -240,13 +224,7 @@ impl SumFactor {
 
         let gaussian = Gaussian::from_pi_tau(new_pi, new_tau);
 
-        if variable == self.sum {
-            println!("SumFactor: sum.id={}, msg={:?}", variable.index, gaussian);
-        } else {
-            println!("SumFactor: term.id={}, msg={:?}", variable.index, gaussian);
-        }
-
-        variable_arena.get_mut(variable).unwrap().update_value(self.id, gaussian);
+        variable_arena.get_mut(variable).unwrap().update_message(self.id, gaussian);
     }
 
     pub fn update_sum(&self, variable_arena: &mut VariableArena) {
@@ -298,16 +276,16 @@ impl SumFactor {
 
         v[index] = self.sum;
 
-        for term in v {
+        for term in &v {
             let value = variable_arena
-                .get(term)
+                .get(*term)
                 .map(|variable| variable.get_value())
                 .unwrap();
 
             y.push(value);
 
             let value = variable_arena
-                .get(term)
+                .get(*term)
                 .map(|variable| variable.get_message(self.id))
                 .unwrap();