[KG] save embeddings in NumPy (#900)

* fix loading and saving.

* use numpy.

apps/kg/models/mxnet/tensor_models.py

@@ -86,9 +86,9 @@ class ExternalEmbedding:
         return nd.concat(*data, dim=0)
 
     def save(self, path, name):
-        emb_fname = os.path.join(path, name+'.emb')
-        nd.save(emb_fname, self.emb)
+        emb_fname = os.path.join(path, name+'.npy')
+        np.save(emb_fname, self.emb.asnumpy())
 
     def load(self, path, name):
-        emb_fname = os.path.join(path, name+'.emb')
-        self.emb = nd.load(emb_fname)[0]
+        emb_fname = os.path.join(path, name+'.npy')
+        self.emb = nd.array(np.load(emb_fname))

apps/kg/models/pytorch/tensor_models.py

@@ -96,7 +96,7 @@ class ExternalEmbedding:
         return th.cat(data, 0)
 
     def save(self, path, name):
-        file_name = os.path.join(path, name)
+        file_name = os.path.join(path, name+'.npy')
         np.save(file_name, self.emb.cpu().detach().numpy())
 
     def load(self, path, name):