Add count_params method to Link

chainer/link.py

@@ -578,6 +578,32 @@ def serialize(self, serializer):
         for name in self._persistent:
             d[name] = serializer(name, d[name])
 
+    def count_params(self):
+        """Counts the total number of parameters.
+
+        This method counts the total number of scalar values included in all
+        the :class:`~chainer.Parameter`\\ s held by this link and its
+        descendants.
+
+        If the link containts uninitialized parameters, this method raises a
+        warning.
+
+        Returns:
+            The total size of parameters (int)
+
+        """
+
+        size = 0
+        for name, param in self.namedparams():
+            if param.array is None:
+                warnings.warn(
+                    'Parameter \'{}\' has not been initialized, so the '
+                    'resulting count will not include the number of parameters'
+                    ' in it.'.format(name))
+                continue
+            size += param.size
+        return size
+
 
 class Chain(Link):
 

tests/chainer_tests/test_link.py

@@ -1,5 +1,6 @@
 import copy
 import unittest
+import warnings
 
 import mock
 import numpy
@@ -468,6 +469,21 @@ def test_update_enabled(self):
         self.link.enable_update()
         self.assertTrue(self.link.update_enabled)
 
+    def test_count_params(self):
+        with warnings.catch_warnings(record=True) as w:
+            warnings.simplefilter('always')
+            self.link.count_params()
+        assert len(w) == 2
+        assert w[0].category is UserWarning
+        assert self.link.count_params() == 8
+
+        self.link.u.initialize((2, 3))
+        self.link.v.initialize((2, 3))
+        with warnings.catch_warnings(record=True) as w:
+            warnings.simplefilter('always')
+            self.link.count_params()
+        assert not w
+
 
 class CountParameter(chainer.Parameter):
 
@@ -789,6 +805,20 @@ def test_serialize(self):
         mocks['l1'].assert_called_with('x', self.l1.x.data)
         mocks['l2'].assert_called_with('x', self.l2.x.data)
 
+    def test_count_params(self):
+        with warnings.catch_warnings(record=True) as w:
+            warnings.simplefilter('always')
+            self.c2.count_params()
+        assert len(w) == 1
+        assert w[0].category is UserWarning
+        assert self.c1.count_params() == 8
+
+        self.c2.l3.x.initialize((3,))
+        with warnings.catch_warnings(record=True) as w:
+            warnings.simplefilter('always')
+            self.c2.count_params()
+        assert not w
+
 
 class TestChainList(unittest.TestCase):
 
@@ -1102,6 +1132,20 @@ def test_serialize(self):
         mocks['0'].assert_called_with('y', l1.y.data)
         mocks['1'].assert_called_with('x', l2.x.data)
 
+    def test_count_params(self):
+        with warnings.catch_warnings(record=True) as w:
+            warnings.simplefilter('always')
+            self.c2.count_params()
+        assert len(w) == 1
+        assert w[0].category is UserWarning
+        assert self.c1.count_params() == 8
+
+        self.c2[0][0].y.initialize((2, 3))
+        with warnings.catch_warnings(record=True) as w:
+            warnings.simplefilter('always')
+            self.c2.count_params()
+        assert not w
+
 
 @attr.ideep
 class TestIntel64(unittest.TestCase):