Add model constructor feedforward_symmetric

gordo_components/model/factories/feedforward_autoencoder.py

@@ -70,3 +70,32 @@ def feedforward_model(
 
     model.compile(optimizer="adam", loss="mean_squared_error", metrics=["accuracy"])
     return model
+
+
+@register_model_builder(type="KerasAutoEncoder")
+@register_model_builder(type="KerasBaseEstimator")
+def feedforward_symmetric(
+    n_features: int, dims: List[int], funcs: List[str], **kwargs
+) -> keras.models.Sequential:
+    """
+    Builds a symmetrical feedforward model
+
+    Parameters:
+    ----------
+        n_features: int
+                    Number of input and output neurons
+        dim: List[int]
+             Number of neurons per layers for the encoder, reversed for the decoder.
+             Must have len > 0
+        funcs: List[str]
+            Activation functions for the internal layers
+
+    Returns:
+    -------
+    keras.models.Sequential
+
+    """
+    if len(dims) == 0:
+        raise ValueError("Parameter dims must have len > 0")
+    return feedforward_model(n_features, dims, dims[::-1], funcs, funcs[::-1], **kwargs)
+

gordo_components/serializer/serializer.py

@@ -35,7 +35,7 @@ def dumps(model: GordoBase) -> bytes:
 
     >>> from gordo_components.model.models import KerasAutoEncoder
     >>> from gordo_components import serializer
-    >>> model = KerasAutoEncoder('feedforward_model')
+    >>> model = KerasAutoEncoder('feedforward_symmetric')
     >>> serialized = serializer.dumps(model)
     >>> assert isinstance(serialized, bytes)
     >>> model_clone = serializer.loads(serialized)

tests/test_feedforward_autoencoder.py

@@ -0,0 +1,38 @@
+# -*- coding: utf-8 -*-
+
+import unittest
+from unittest import mock
+
+from gordo_components.model.factories.feedforward_autoencoder import (
+    feedforward_symmetric,
+)
+
+
+def feedforward_model_mocker(n_features: int, enc_dim, dec_dim, enc_func, dec_func):
+    return n_features, enc_dim, dec_dim, enc_func, dec_func
+
+
+class FeedForwardAutoEncoderTestCase(unittest.TestCase):
+    @mock.patch(
+        "gordo_components.model.factories.feedforward_autoencoder.feedforward_model",
+        side_effect=feedforward_model_mocker,
+    )
+    def test_feedforward_symmetric_basic(self, _):
+        """
+        Test that feedforward_symmetric calls feedforward_model correctly
+        """
+        n_features, enc_dim, dec_dim, enc_func, dec_func = feedforward_symmetric(
+            5, [4, 3, 2, 1], ["relu", "relu", "tanh", "tanh"]
+        )
+        self.assertEqual(n_features, 5)
+        self.assertEqual(enc_dim, [4, 3, 2, 1])
+        self.assertEqual(dec_dim, [1, 2, 3, 4])
+        self.assertEqual(enc_func, ["relu", "relu", "tanh", "tanh"])
+        self.assertEqual(dec_func, ["tanh", "tanh", "relu", "relu"])
+
+    def test_feedforward_symmetric_checks_dims(self):
+        """
+        Test that feedforward_symmetric validates parameter requirements
+        """
+        with self.assertRaises(ValueError):
+            feedforward_symmetric(4, [], [])