Example #1
0
 def test_loss_reduction_must_be_same(self):
     """Tests the loss reduction must be the same for different heads."""
     head1 = multi_label_head.MultiLabelHead(
         n_classes=2,
         name='head1',
         loss_reduction=losses_utils.ReductionV2.SUM_OVER_BATCH_SIZE)
     head2 = multi_label_head.MultiLabelHead(
         n_classes=3,
         name='head2',
         loss_reduction=losses_utils.ReductionV2.AUTO)
     multi_head = multi_head_lib.MultiHead([head1, head2])
     logits = {
         'head1':
         np.array([[-10., 10.], [-15., 10.]], dtype=np.float32),
         'head2':
         np.array([[20., -20., 20.], [-30., 20., -20.]], dtype=np.float32),
     }
     labels = {
         'head1': np.array([[1, 0], [1, 1]], dtype=np.int64),
         'head2': np.array([[0, 1, 0], [1, 1, 0]], dtype=np.int64),
     }
     with self.assertRaisesRegexp(ValueError, 'must be the same'):
         multi_head.create_estimator_spec(
             features={'x': np.array(((42, ), ), dtype=np.int32)},
             mode=ModeKeys.TRAIN,
             logits=logits,
             labels=labels)
Example #2
0
    def test_train_loss_logits_tensor_wrong_shape(self):
        """Tests loss with a logits Tensor of the wrong shape."""
        weights1 = np.array([[1.], [2.]], dtype=np.float32)
        weights2 = np.array([[2.], [3.]])
        head1 = multi_label_head.MultiLabelHead(n_classes=2,
                                                name='head1',
                                                weight_column='weights1')
        head2 = multi_label_head.MultiLabelHead(n_classes=3,
                                                name='head2',
                                                weight_column='weights2')
        multi_head = multi_head_lib.MultiHead([head1, head2],
                                              head_weights=[1., 2.])

        # logits tensor is 2x6 instead of 2x5
        logits = np.array([[-10., 10., 20., -20., 20., 70.],
                           [-15., 10., -30., 20., -20., 80.]],
                          dtype=np.float32)
        labels = {
            'head1': np.array([[1, 0], [1, 1]], dtype=np.int64),
            'head2': np.array([[0, 1, 0], [1, 1, 0]], dtype=np.int64),
        }
        with self.assertRaisesRegexp(ValueError, r'Could not split logits'):
            multi_head.loss(features={
                'x': np.array(((42, ), ), dtype=np.int32),
                'weights1': weights1,
                'weights2': weights2
            },
                            mode=ModeKeys.TRAIN,
                            logits=logits,
                            labels=labels)
Example #3
0
 def test_head_weights_wrong_size(self):
   head1 = multi_label_head.MultiLabelHead(n_classes=2, name='head1')
   head2 = multi_label_head.MultiLabelHead(n_classes=3, name='head2')
   with self.assertRaisesRegexp(
       ValueError,
       r'heads and head_weights must have the same size\. '
       r'Given len\(heads\): 2. Given len\(head_weights\): 1\.'):
     multi_head_lib.MultiHead([head1, head2], head_weights=[1.])
Example #4
0
    def test_train_create_loss_two_heads_with_weights(self):
        # Use different example weighting for each head weighting.
        weights1 = np.array([[1.], [2.]], dtype=np.float32)
        weights2 = np.array([[2.], [3.]])
        head1 = multi_label_head.MultiLabelHead(n_classes=2,
                                                name='head1',
                                                weight_column='weights1')
        head2 = multi_label_head.MultiLabelHead(n_classes=3,
                                                name='head2',
                                                weight_column='weights2')
        multi_head = multi_head_lib.MultiHead([head1, head2],
                                              head_weights=[1., 2.])

        logits = {
            'head1':
            np.array([[-10., 10.], [-15., 10.]], dtype=np.float32),
            'head2':
            np.array([[20., -20., 20.], [-30., 20., -20.]], dtype=np.float32),
        }
        labels = {
            'head1': np.array([[1, 0], [1, 1]], dtype=np.int64),
            'head2': np.array([[0, 1, 0], [1, 1, 0]], dtype=np.int64),
        }
        training_loss = multi_head.loss(logits=logits,
                                        labels=labels,
                                        features={
                                            'x':
                                            np.array(((42, ), ),
                                                     dtype=np.int32),
                                            'weights1':
                                            weights1,
                                            'weights2':
                                            weights2
                                        },
                                        mode=model_fn.ModeKeys.TRAIN)
        tol = 1e-3
        # loss of the first head is [[(10 + 10) / 2], [(15 + 0) / 2]]
        # = [10, 7.5]
        # training_loss = (1 * 10 + 2 * 7.5) / 2 = 12.5
        # head-weighted unreduced_loss = 1 * [10, 7.5]
        # loss of the second head is [[(20 + 20 + 20) / 3], [(30 + 0 + 0) / 3]]
        # = [20, 10]
        # training_loss = (2 * 20 + 3 * 10) / 2 = 35
        # head-weighted unreduced_loss = 2 * [20, 10]
        # head-weighted training_loss = 1 * 12.5 + 2 * 35 = 82.5
        self.assertAllClose(82.5,
                            self.evaluate(training_loss),
                            rtol=tol,
                            atol=tol)
Example #5
0
    def test_train_one_head_with_optimizer(self):
        head1 = multi_label_head.MultiLabelHead(n_classes=2, name='head1')
        multi_head = multi_head_lib.MultiHead([head1])

        logits = {
            'head1': np.array([[-10., 10.], [-15., 10.]], dtype=np.float32)
        }
        labels = {'head1': np.array([[1, 0], [1, 1]], dtype=np.int64)}
        features = {'x': np.array(((42, ), ), dtype=np.int32)}
        # For large logits, sigmoid cross entropy loss is approximated as:
        # loss = labels * (logits < 0) * (-logits) +
        #        (1 - labels) * (logits > 0) * logits =>
        # expected_unweighted_loss = [[10., 10.], [15., 0.]]
        # loss = ((10 + 10) / 2 + (15 + 0) / 2) / 2 = 8.75
        expected_loss = 8.75
        tol = 1e-3
        loss = multi_head.loss(logits=logits,
                               labels=labels,
                               features=features,
                               mode=ModeKeys.TRAIN)
        self.assertAllClose(expected_loss,
                            self.evaluate(loss),
                            rtol=tol,
                            atol=tol)
        if tf.executing_eagerly():
            return

        expected_train_result = 'my_train_op'

        class _Optimizer(optimizer_v2.OptimizerV2):
            def get_updates(self, loss, params):
                del params
                return [
                    tf.strings.join([
                        tf.constant(expected_train_result),
                        tf.strings.as_string(loss, precision=3)
                    ])
                ]

            def get_config(self):
                config = super(_Optimizer, self).get_config()
                return config

        spec = multi_head.create_estimator_spec(
            features=features,
            mode=ModeKeys.TRAIN,
            logits=logits,
            labels=labels,
            optimizer=_Optimizer('my_optimizer'),
            trainable_variables=[
                tf.Variable([1.0, 2.0], dtype=tf.dtypes.float32)
            ])

        with self.cached_session() as sess:
            test_lib._initialize_variables(self, spec.scaffold)
            loss, train_result = sess.run((spec.loss, spec.train_op))
            self.assertAllClose(expected_loss, loss, rtol=tol, atol=tol)
            self.assertEqual(
                six.b('{0:s}{1:.3f}'.format(expected_train_result,
                                            expected_loss)), train_result)
Example #6
0
  def test_train_one_head(self):
    head1 = multi_label_head.MultiLabelHead(n_classes=2, name='head1')
    multi_head = multi_head_lib.MultiHead([head1])

    logits = {'head1': np.array([[-10., 10.], [-15., 10.]], dtype=np.float32)}
    labels = {'head1': np.array([[1, 0], [1, 1]], dtype=np.int64)}
    features = {'x': np.array(((42,),), dtype=np.int32)}
    # For large logits, sigmoid cross entropy loss is approximated as:
    # loss = labels * (logits < 0) * (-logits) +
    #        (1 - labels) * (logits > 0) * logits =>
    # expected_unweighted_loss = [[10., 10.], [15., 0.]]
    # loss = ((10 + 10) / 2 + (15 + 0) / 2) / 2 = 8.75
    expected_loss = 8.75
    tol = 1e-3
    loss = multi_head.loss(
        logits=logits,
        labels=labels,
        features=features,
        mode=model_fn.ModeKeys.TRAIN)
    self.assertAllClose(expected_loss, self.evaluate(loss), rtol=tol, atol=tol)
    if context.executing_eagerly():
      return

    expected_train_result = 'my_train_op'
    def _train_op_fn(loss):
      return string_ops.string_join(
          [constant_op.constant(expected_train_result),
           string_ops.as_string(loss, precision=3)])
    spec = multi_head.create_estimator_spec(
        features=features,
        mode=model_fn.ModeKeys.TRAIN,
        logits=logits,
        labels=labels,
        train_op_fn=_train_op_fn)
    self.assertIsNotNone(spec.loss)
    self.assertEqual({}, spec.eval_metric_ops)
    self.assertIsNotNone(spec.train_op)
    self.assertIsNone(spec.export_outputs)
    test_lib._assert_no_hooks(self, spec)
    # Assert predictions, loss, train_op, and summaries.
    with self.cached_session() as sess:
      test_lib._initialize_variables(self, spec.scaffold)
      self.assertIsNotNone(spec.scaffold.summary_op)
      loss, train_result, summary_str = sess.run((spec.loss, spec.train_op,
                                                  spec.scaffold.summary_op))
      self.assertAllClose(expected_loss, loss, rtol=tol, atol=tol)
      self.assertEqual(
          six.b('{0:s}{1:.3f}'.format(expected_train_result, expected_loss)),
          train_result)
      test_lib._assert_simple_summaries(self, {
          metric_keys.MetricKeys.LOSS: expected_loss,
          metric_keys.MetricKeys.LOSS + '/head1': expected_loss,
      }, summary_str, tol)
Example #7
0
    def test_train_one_head_with_optimizer(self):
        head1 = multi_label_head.MultiLabelHead(n_classes=2, name='head1')
        multi_head = multi_head_lib.MultiHead([head1])

        logits = {
            'head1': np.array([[-10., 10.], [-15., 10.]], dtype=np.float32)
        }
        labels = {'head1': np.array([[1, 0], [1, 1]], dtype=np.int64)}
        features = {'x': np.array(((42, ), ), dtype=np.int32)}
        # For large logits, sigmoid cross entropy loss is approximated as:
        # loss = labels * (logits < 0) * (-logits) +
        #        (1 - labels) * (logits > 0) * logits =>
        # expected_unweighted_loss = [[10., 10.], [15., 0.]]
        # loss = ((10 + 10) / 2 + (15 + 0) / 2) / 2 = 8.75
        expected_loss = 8.75
        tol = 1e-3
        loss = multi_head.loss(logits=logits,
                               labels=labels,
                               features=features,
                               mode=model_fn.ModeKeys.TRAIN)
        self.assertAllClose(expected_loss,
                            self.evaluate(loss),
                            rtol=tol,
                            atol=tol)
        if context.executing_eagerly():
            return

        expected_train_result = 'my_train_op'

        class _Optimizer(object):
            def minimize(self, loss, global_step):
                del global_step
                return string_ops.string_join([
                    constant_op.constant(expected_train_result),
                    string_ops.as_string(loss, precision=3)
                ])

        spec = multi_head.create_estimator_spec(features=features,
                                                mode=model_fn.ModeKeys.TRAIN,
                                                logits=logits,
                                                labels=labels,
                                                optimizer=_Optimizer())
        with self.cached_session() as sess:
            test_lib._initialize_variables(self, spec.scaffold)
            loss, train_result = sess.run((spec.loss, spec.train_op))
            self.assertAllClose(expected_loss, loss, rtol=tol, atol=tol)
            self.assertEqual(
                six.b('{0:s}{1:.3f}'.format(expected_train_result,
                                            expected_loss)), train_result)
Example #8
0
  def test_train_create_loss_one_head(self):
    head1 = multi_label_head.MultiLabelHead(n_classes=2, name='head1')
    multi_head = multi_head_lib.MultiHead([head1])

    logits = {'head1': np.array([[-10., 10.], [-15., 10.]], dtype=np.float32)}
    labels = {'head1': np.array([[1, 0], [1, 1]], dtype=np.int64)}
    loss = multi_head.loss(
        logits=logits,
        labels=labels,
        features={'x': np.array(((42,),), dtype=np.int32)},
        mode=model_fn.ModeKeys.TRAIN)
    tol = 1e-3
    # Unreduced loss of the head is [[(10 + 10) / 2], (15 + 0) / 2]
    # (averaged over classes, averaged over examples).
    # loss = sum(unreduced_loss) / 2 = sum([10, 7.5]) / 2 = 8.75
    self.assertAllClose(8.75, self.evaluate(loss), rtol=tol, atol=tol)
Example #9
0
  def test_predict_two_heads_logits_dict(self):
    """Tests predict with logits as dict."""
    head1 = multi_label_head.MultiLabelHead(n_classes=2, name='head1')
    head2 = multi_label_head.MultiLabelHead(n_classes=3, name='head2')
    multi_head = multi_head_lib.MultiHead([head1, head2])

    logits = {
        'head1': np.array([[-1., 1.], [-1.5, 1.]], dtype=np.float32),
        'head2': np.array([[2., -2., 2.], [-3., 2., -2.]], dtype=np.float32)
    }
    expected_probabilities = {
        'head1': nn.sigmoid(logits['head1']),
        'head2': nn.sigmoid(logits['head2']),
    }
    pred_keys = prediction_keys.PredictionKeys

    predictions = multi_head.predictions(logits)
    self.assertAllClose(
        logits['head1'],
        self.evaluate(predictions[('head1', pred_keys.LOGITS)]))
    self.assertAllClose(
        logits['head2'],
        self.evaluate(predictions[('head2', pred_keys.LOGITS)]))
    self.assertAllClose(
        expected_probabilities['head1'],
        self.evaluate(predictions[('head1', pred_keys.PROBABILITIES)]))
    self.assertAllClose(
        expected_probabilities['head2'],
        self.evaluate(predictions[('head2', pred_keys.PROBABILITIES)]))
    if context.executing_eagerly():
      return

    spec = multi_head.create_estimator_spec(
        features={'x': np.array(((42,),), dtype=np.int32)},
        mode=model_fn.ModeKeys.PREDICT,
        logits=logits)
    self.assertItemsEqual(
        (test_lib._DEFAULT_SERVING_KEY, 'predict', 'head1',
         'head1/classification', 'head1/predict', 'head2',
         'head2/classification', 'head2/predict'), spec.export_outputs.keys())
    # Assert predictions and export_outputs.
    with self.cached_session() as sess:
      test_lib._initialize_variables(self, spec.scaffold)
      self.assertIsNone(spec.scaffold.summary_op)
      predictions = sess.run(spec.predictions)
      self.assertAllClose(
          logits['head1'],
          predictions[('head1', pred_keys.LOGITS)])
      self.assertAllClose(
          logits['head2'],
          predictions[('head2', pred_keys.LOGITS)])
      self.assertAllClose(
          expected_probabilities['head1'],
          predictions[('head1', pred_keys.PROBABILITIES)])
      self.assertAllClose(
          expected_probabilities['head2'],
          predictions[('head2', pred_keys.PROBABILITIES)])

      self.assertAllClose(
          expected_probabilities['head1'],
          sess.run(spec.export_outputs[test_lib._DEFAULT_SERVING_KEY].scores))
      self.assertAllClose(
          expected_probabilities['head1'],
          sess.run(spec.export_outputs['head1'].scores))
      self.assertAllClose(
          expected_probabilities['head2'],
          sess.run(spec.export_outputs['head2'].scores))
      self.assertAllClose(
          expected_probabilities['head1'],
          sess.run(
              spec.export_outputs['predict'].outputs['head1/probabilities']))
      self.assertAllClose(
          expected_probabilities['head2'],
          sess.run(
              spec.export_outputs['predict'].outputs['head2/probabilities']))
      self.assertAllClose(
          expected_probabilities['head1'],
          sess.run(
              spec.export_outputs['head1/predict'].outputs['probabilities']))
      self.assertAllClose(
          expected_probabilities['head2'],
          sess.run(
              spec.export_outputs['head2/predict'].outputs['probabilities']))
Example #10
0
  def test_train_with_regularization_losses(self):
    head1 = multi_label_head.MultiLabelHead(n_classes=2, name='head1')
    head2 = multi_label_head.MultiLabelHead(n_classes=3, name='head2')
    multi_head = multi_head_lib.MultiHead(
        [head1, head2], head_weights=[1., 2.])

    logits = {
        'head1': np.array([[-10., 10.], [-15., 10.]], dtype=np.float32),
        'head2': np.array([[20., -20., 20.], [-30., 20., -20.]],
                          dtype=np.float32),
    }
    labels = {
        'head1': np.array([[1, 0], [1, 1]], dtype=np.int64),
        'head2': np.array([[0, 1, 0], [1, 1, 0]], dtype=np.int64),
    }
    features = {'x': np.array(((42,),), dtype=np.int32)}
    regularization_losses = [1.5, 0.5]

    # For large logits, sigmoid cross entropy loss is approximated as:
    # loss = labels * (logits < 0) * (-logits) +
    #        (1 - labels) * (logits > 0) * logits =>
    # head1: expected_unweighted_loss = [[10., 10.], [15., 0.]]
    # loss1 = ((10 + 10) / 2 + (15 + 0) / 2) / 2 = 8.75
    # head2: expected_unweighted_loss = [[20., 20., 20.], [30., 0., 0]]
    # loss2 = ((20 + 20 + 20) / 3 + (30 + 0 + 0) / 3) / 2 = 15
    # Average over classes, weighted sum over batch and heads.
    # weights = [1., 2.]
    # merged_training_loss = 1. * loss1 + 2. * loss2
    # training_loss = merged_training_loss + regularization_loss
    #               = 1. * loss1 + 2. * loss2 + sum([1.5, 0.5])
    expected_loss_head1 = 8.75
    expected_loss_head2 = 15.0
    expected_regularization_loss = 2.
    # training loss.
    expected_loss = (1. * expected_loss_head1 + 2. * expected_loss_head2
                     + expected_regularization_loss)
    tol = 1e-3
    loss = multi_head.loss(
        logits=logits,
        labels=labels,
        features=features,
        mode=model_fn.ModeKeys.TRAIN,
        regularization_losses=regularization_losses)
    self.assertAllClose(expected_loss, self.evaluate(loss), rtol=tol, atol=tol)
    if context.executing_eagerly():
      return

    keys = metric_keys.MetricKeys
    expected_train_result = 'my_train_op'
    def _train_op_fn(loss):
      return string_ops.string_join(
          [constant_op.constant(expected_train_result),
           string_ops.as_string(loss, precision=3)])

    spec = multi_head.create_estimator_spec(
        features=features,
        mode=model_fn.ModeKeys.TRAIN,
        logits=logits,
        labels=labels,
        train_op_fn=_train_op_fn,
        regularization_losses=regularization_losses)
    self.assertIsNotNone(spec.loss)
    self.assertEqual({}, spec.eval_metric_ops)
    self.assertIsNotNone(spec.train_op)
    self.assertIsNone(spec.export_outputs)
    test_lib._assert_no_hooks(self, spec)
    # Assert predictions, loss, train_op, and summaries.
    with self.cached_session() as sess:
      test_lib._initialize_variables(self, spec.scaffold)
      self.assertIsNotNone(spec.scaffold.summary_op)
      loss, train_result, summary_str = sess.run((spec.loss, spec.train_op,
                                                  spec.scaffold.summary_op))
      self.assertAllClose(expected_loss, loss, rtol=tol, atol=tol)
      self.assertEqual(
          six.b('{0:s}{1:.3f}'.format(expected_train_result, expected_loss)),
          train_result)
      test_lib._assert_simple_summaries(self, {
          keys.LOSS_REGULARIZATION: expected_regularization_loss,
          keys.LOSS: expected_loss,
          keys.LOSS + '/head1': expected_loss_head1,
          keys.LOSS + '/head2': expected_loss_head2,
      }, summary_str, tol)
Example #11
0
 def test_name(self):
   head1 = multi_label_head.MultiLabelHead(n_classes=2, name='head1')
   head2 = multi_label_head.MultiLabelHead(n_classes=3, name='head2')
   multi_head = multi_head_lib.MultiHead([head1, head2])
   self.assertEqual('head1_head2', multi_head.name)
Example #12
0
 def test_head_name_missing(self):
   head1 = multi_label_head.MultiLabelHead(n_classes=2, name='head1')
   head2 = multi_label_head.MultiLabelHead(n_classes=3)
   with self.assertRaisesRegexp(
       ValueError, r'All given heads must have name specified\.'):
     multi_head_lib.MultiHead([head1, head2])
Example #13
0
  def test_eval_two_heads_with_weights(self):
    head1 = multi_label_head.MultiLabelHead(n_classes=2, name='head1')
    head2 = multi_label_head.MultiLabelHead(n_classes=3, name='head2')
    multi_head = multi_head_lib.MultiHead(
        [head1, head2], head_weights=[1., 2.])

    logits = {
        'head1': np.array([[-10., 10.], [-15., 10.]], dtype=np.float32),
        'head2': np.array([[20., -20., 20.], [-30., 20., -20.]],
                          dtype=np.float32),
    }
    labels = {
        'head1': np.array([[1, 0], [1, 1]], dtype=np.int64),
        'head2': np.array([[0, 1, 0], [1, 1, 0]], dtype=np.int64),
    }
    features = {'x': np.array(((42,),), dtype=np.int32)}
    # For large logits, sigmoid cross entropy loss is approximated as:
    # loss = labels * (logits < 0) * (-logits) +
    #        (1 - labels) * (logits > 0) * logits =>
    # head1: expected_unweighted_loss = [[10., 10.], [15., 0.]]
    # loss = ((10 + 10) / 2 + (15 + 0) / 2) / 2 = 8.75
    # head2: expected_unweighted_loss = [[20., 20., 20.], [30., 0., 0]]
    # loss = ((20 + 20 + 20) / 3 + (30 + 0 + 0) / 3) / 2 = 15
    expected_loss_head1 = 8.75
    expected_loss_head2 = 15.
    expected_loss = 1. * expected_loss_head1 + 2. * expected_loss_head2
    tol = 1e-3
    keys = metric_keys.MetricKeys
    expected_metrics = {
        keys.LOSS + '/head1': expected_loss_head1,
        keys.LOSS + '/head2': expected_loss_head2,
        # Average loss over examples.
        keys.LOSS_MEAN + '/head1': expected_loss_head1,
        keys.LOSS_MEAN + '/head2': expected_loss_head2,
        # auc and auc_pr cannot be reliably calculated for only 4-6 samples, but
        # this assert tests that the algorithm remains consistent.
        # TODO(yhliang): update metrics
        # keys.AUC + '/head1': 0.1667,
        # keys.AUC + '/head2': 0.3333,
        # keys.AUC_PR + '/head1': 0.6667,
        # keys.AUC_PR + '/head2': 0.5000,
    }

    if context.executing_eagerly():
      loss = multi_head.loss(
          logits, labels, features=features, mode=model_fn.ModeKeys.EVAL)
      self.assertIsNotNone(loss)
      self.assertAllClose(expected_loss, loss, rtol=tol, atol=tol)

      eval_metrics = multi_head.metrics()
      updated_metrics = multi_head.update_metrics(
          eval_metrics, features, logits, labels)
      self.assertItemsEqual(expected_metrics.keys(), updated_metrics.keys())
      self.assertAllClose(
          expected_metrics,
          {k: updated_metrics[k].result() for k in updated_metrics},
          rtol=tol,
          atol=tol)
      return

    spec = multi_head.create_estimator_spec(
        features=features,
        mode=model_fn.ModeKeys.EVAL,
        logits=logits,
        labels=labels)
    # Assert spec contains expected tensors.
    self.assertIsNotNone(spec.loss)
    self.assertItemsEqual(expected_metrics.keys(), spec.eval_metric_ops.keys())
    self.assertIsNone(spec.train_op)
    self.assertIsNone(spec.export_outputs)
    test_lib._assert_no_hooks(self, spec)
    # Assert predictions, loss, and metrics.
    with self.cached_session() as sess:
      test_lib._initialize_variables(self, spec.scaffold)
      self.assertIsNone(spec.scaffold.summary_op)
      value_ops = {k: spec.eval_metric_ops[k][0] for k in spec.eval_metric_ops}
      update_ops = {k: spec.eval_metric_ops[k][1] for k in spec.eval_metric_ops}
      loss, _ = sess.run((spec.loss, update_ops))
      self.assertAllClose(expected_loss, loss, rtol=tol, atol=tol)
      # Check results of value ops (in `metrics`).
      self.assertAllClose(
          expected_metrics, {k: value_ops[k].eval() for k in value_ops},
          rtol=tol,
          atol=tol)
Example #14
0
    def test_train_two_heads_with_weights(self):
        head1 = multi_label_head.MultiLabelHead(n_classes=2, name='head1')
        head2 = multi_label_head.MultiLabelHead(n_classes=3, name='head2')
        multi_head = multi_head_lib.MultiHead([head1, head2],
                                              head_weights=[1., 2.])

        logits = {
            'head1':
            np.array([[-10., 10.], [-15., 10.]], dtype=np.float32),
            'head2':
            np.array([[20., -20., 20.], [-30., 20., -20.]], dtype=np.float32),
        }
        expected_probabilities = {
            'head1': tf.math.sigmoid(logits['head1']),
            'head2': tf.math.sigmoid(logits['head2']),
        }
        labels = {
            'head1': np.array([[1, 0], [1, 1]], dtype=np.int64),
            'head2': np.array([[0, 1, 0], [1, 1, 0]], dtype=np.int64),
        }
        features = {'x': np.array(((42, ), ), dtype=np.int32)}
        # For large logits, sigmoid cross entropy loss is approximated as:
        # loss = labels * (logits < 0) * (-logits) +
        #        (1 - labels) * (logits > 0) * logits =>
        # head1: expected_unweighted_loss = [[10., 10.], [15., 0.]]
        # loss = ((10 + 10) / 2 + (15 + 0) / 2) / 2 = 8.75
        # head2: expected_unweighted_loss = [[20., 20., 20.], [30., 0., 0]]
        # loss = ((20 + 20 + 20) / 3 + (30 + 0 + 0) / 3) / 2 = 15
        # Average over classes, weighted sum over batch and heads.
        expected_loss_head1 = 8.75
        expected_loss_head2 = 15.0
        expected_loss = 1. * expected_loss_head1 + 2. * expected_loss_head2
        tol = 1e-3
        loss = multi_head.loss(logits=logits,
                               labels=labels,
                               features=features,
                               mode=ModeKeys.TRAIN)
        self.assertAllClose(expected_loss,
                            self.evaluate(loss),
                            rtol=tol,
                            atol=tol)
        if tf.executing_eagerly():
            return

        expected_train_result = 'my_train_op'

        def _train_op_fn(loss):
            return tf.strings.join([
                tf.constant(expected_train_result),
                tf.strings.as_string(loss, precision=3)
            ])

        spec = multi_head.create_estimator_spec(features=features,
                                                mode=ModeKeys.TRAIN,
                                                logits=logits,
                                                labels=labels,
                                                train_op_fn=_train_op_fn)
        self.assertIsNotNone(spec.loss)
        self.assertEqual({}, spec.eval_metric_ops)
        self.assertIsNotNone(spec.train_op)
        self.assertIsNone(spec.export_outputs)
        test_lib._assert_no_hooks(self, spec)
        # Assert predictions, loss, train_op, and summaries.
        with self.cached_session() as sess:
            test_lib._initialize_variables(self, spec.scaffold)
            self.assertIsNotNone(spec.scaffold.summary_op)
            loss, train_result, summary_str, predictions = sess.run(
                (spec.loss, spec.train_op, spec.scaffold.summary_op,
                 spec.predictions))
            self.assertAllClose(
                logits['head1'],
                predictions[('head1', prediction_keys.PredictionKeys.LOGITS)])
            self.assertAllClose(
                expected_probabilities['head1'],
                predictions[('head1',
                             prediction_keys.PredictionKeys.PROBABILITIES)])
            self.assertAllClose(
                logits['head2'],
                predictions[('head2', prediction_keys.PredictionKeys.LOGITS)])
            self.assertAllClose(
                expected_probabilities['head2'],
                predictions[('head2',
                             prediction_keys.PredictionKeys.PROBABILITIES)])
            self.assertAllClose(expected_loss, loss, rtol=tol, atol=tol)
            self.assertEqual(
                six.b('{0:s}{1:.3f}'.format(expected_train_result,
                                            expected_loss)), train_result)
            test_lib._assert_simple_summaries(
                self, {
                    metric_keys.MetricKeys.LOSS: expected_loss,
                    metric_keys.MetricKeys.LOSS + '/head1':
                    expected_loss_head1,
                    metric_keys.MetricKeys.LOSS + '/head2':
                    expected_loss_head2,
                }, summary_str, tol)