Remove logpdf from internal nodes (closes #44).

src/spn.py

@@ -63,8 +63,6 @@ def logprob(self, event):
     def prob(self, event):
         lp = self.logprob(event)
         return exp(lp)
-    def logpdf(self, x):
-        raise NotImplementedError()
     def condition(self, event):
         raise NotImplementedError()
     def mutual_information(self, A, B):
@@ -164,10 +162,6 @@ def logprob(self, event):
         logps = [spn.logprob(event_dnf) for spn in self.children]
         return logsumexp([p + w for (p, w) in zip(logps, self.weights)])
 
-    def logpdf(self, x):
-        logps = [spn.logpdf(x) for spn in self.children]
-        return logsumexp([p + w for (p, w) in zip(logps, self.weights)])
-
     def condition(self, event):
         logps_condt = [spn.logprob(event) for spn in self.children]
         indexes = [i for i, lp in enumerate(logps_condt) if not isinf_neg(lp)]
@@ -287,12 +281,6 @@ def sample_func(self, func, N, rng):
         samples = self.sample_subset(symbols, N, rng)
         return func_evaluate(self, func, samples)
 
-    def logpdf(self, x):
-        assert len(x) == len(self.children)
-        logps = [spn.logpdf(v) for (spn, v) in zip(self.children, x)
-            if x is not None]
-        return logsumexp(logps)
-
     def logprob(self, event):
         event_dnf = dnf_normalize(event)
         if event_dnf is None:
@@ -390,6 +378,8 @@ def sample_subset(self, symbols, N, rng):
     def sample_func(self, func, N, rng):
         samples = self.sample(N, rng)
         return func_evaluate(self, func, samples)
+    def logpdf(self, x):
+        raise NotImplementedError()
 
 # ==============================================================================
 # RealDistribution base class.
@@ -443,9 +433,6 @@ def logcdf(self, x):
         p = logdiffexp(self.dist.logcdf(x), self.logFl)
         return p - self.logZ
 
-    def logpdf(self, x):
-        raise NotImplementedError()
-
     def logprob_values(self, values):
         if values is EmptySet:
             return -inf