Commit 9e686443 authored by Bharath Ramsundar's avatar Bharath Ramsundar Committed by GitHub
Browse files

Merge pull request #252 from rbharath/robust

Experimental Robust Multitask Models
parents eab4109d 49544f33
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+3 −2
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@@ -110,8 +110,8 @@ class TensorflowGraphModel(object):

  def __init__(self, n_tasks, n_features, logdir, layer_sizes=[1000],
               weight_init_stddevs=[.02], bias_init_consts=[1.], penalty=0.0,
               dropouts=[0.5], learning_rate=.001, momentum=".9",
               optimizer="adam", batch_size=50, n_classes=2,
               penalty_type="l2", dropouts=[0.5], learning_rate=.001,
               momentum=".9", optimizer="adam", batch_size=50, n_classes=2,
               train=True, verbosity=None, **kwargs):
    """Constructs the computational graph.

@@ -130,6 +130,7 @@ class TensorflowGraphModel(object):
    self.weight_init_stddevs = weight_init_stddevs
    self.bias_init_consts = bias_init_consts
    self.penalty = penalty
    self.penalty_type = penalty_type
    self.dropouts = dropouts
    self.learning_rate = learning_rate
    self.momentum = momentum
+179 −0
Original line number Diff line number Diff line
from __future__ import print_function
from __future__ import division
from __future__ import unicode_literals

import numpy as np
import tensorflow as tf

from deepchem.models.tensorflow_models import TensorflowGraph
from deepchem.models.tensorflow_models.fcnet import TensorflowMultiTaskRegressor
from deepchem.models.tensorflow_models import model_ops


class RobustMultitaskRegressor(TensorflowMultiTaskRegressor):
  """Implements a neural network for robust multitasking.
  
  Key idea is to have bypass layers that feed directly from features to task
  output. Hopefully will allow tasks to route around bad multitasking.
  """
  def __init__(self, n_tasks, n_features, logdir,
               bypass_layer_sizes=[100],
               bypass_weight_init_stddevs=[.02],
               bypass_bias_init_consts=[1.],
               bypass_dropouts=[.5], **kwargs):
    self.bypass_layer_sizes = bypass_layer_sizes
    self.bypass_weight_init_stddevs = bypass_weight_init_stddevs
    self.bypass_bias_init_consts = bypass_bias_init_consts
    self.bypass_dropouts = bypass_dropouts
    super(RobustMultitaskRegressor, self).__init__(
        n_tasks, n_features, logdir, **kwargs)

  def build(self, graph, name_scopes, training):
    """Constructs the graph architecture as specified in its config.

    This method creates the following Placeholders:
      mol_features: Molecule descriptor (e.g. fingerprint) tensor with shape
        batch_size x num_features.
    """
    num_features = self.n_features 
    placeholder_scope = TensorflowGraph.get_placeholder_scope(
        graph, name_scopes)
    with graph.as_default():
      with placeholder_scope:
        self.mol_features = tf.placeholder(
            tf.float32,
            shape=[None, num_features],
            name='mol_features')

      layer_sizes = self.layer_sizes
      weight_init_stddevs = self.weight_init_stddevs
      bias_init_consts = self.bias_init_consts
      dropouts = self.dropouts

      bypass_layer_sizes = self.bypass_layer_sizes
      bypass_weight_init_stddevs = self.bypass_weight_init_stddevs
      bypass_bias_init_consts = self.bypass_bias_init_consts
      bypass_dropouts = self.bypass_dropouts

      lengths_set = {
          len(layer_sizes),
          len(weight_init_stddevs),
          len(bias_init_consts),
          len(dropouts),
          }
      assert len(lengths_set) == 1, "All layer params must have same length."
      num_layers = lengths_set.pop()
      assert num_layers > 0, "Must have some layers defined."

      bypass_lengths_set = {
          len(bypass_layer_sizes),
          len(bypass_weight_init_stddevs),
          len(bypass_bias_init_consts),
          len(bypass_dropouts),
          }
      assert (len(bypass_lengths_set) == 1,
              "All bypass_layer params must have same length.")
      num_bypass_layers = bypass_lengths_set.pop()

      prev_layer = self.mol_features
      prev_layer_size = num_features 
      for i in range(num_layers):
        # layer has shape [None, layer_sizes[i]]
        ########################################################## DEBUG
        print("Adding weights of shape %s" % str([prev_layer_size, layer_sizes[i]]))
        ########################################################## DEBUG
        layer = tf.nn.relu(model_ops.fully_connected_layer(
            tensor=prev_layer,
            size=layer_sizes[i],
            weight_init=tf.truncated_normal(
                shape=[prev_layer_size, layer_sizes[i]],
                stddev=weight_init_stddevs[i]),
            bias_init=tf.constant(value=bias_init_consts[i],
                                  shape=[layer_sizes[i]])))
        layer = model_ops.dropout(layer, dropouts[i], training)
        prev_layer = layer
        prev_layer_size = layer_sizes[i]

      output = []
      # top_multitask_layer has shape [None, layer_sizes[-1]]
      top_multitask_layer = prev_layer
      for task in range(self.n_tasks):
        # TODO(rbharath): Might want to make it feasible to have multiple
        # bypass layers.
        # Construct task bypass layer
        prev_bypass_layer = self.mol_features
        prev_bypass_layer_size = num_features
        for i in range(num_bypass_layers):
          # bypass_layer has shape [None, bypass_layer_sizes[i]]
          ########################################################## DEBUG
          print("Adding bypass weights of shape %s"
                % str([prev_bypass_layer_size, bypass_layer_sizes[i]]))
          ########################################################## DEBUG
          bypass_layer = tf.nn.relu(model_ops.fully_connected_layer(
            tensor = prev_bypass_layer,
            size = bypass_layer_sizes[i],
            weight_init=tf.truncated_normal(
                shape=[prev_bypass_layer_size, bypass_layer_sizes[i]],
                stddev=bypass_weight_init_stddevs[i]),
            bias_init=tf.constant(value=bypass_bias_init_consts[i],
                                  shape=[bypass_layer_sizes[i]])))
    
          bypass_layer = model_ops.dropout(bypass_layer, bypass_dropouts[i])
          prev_bypass_layer = bypass_layer
          prev_bypass_layer_size = bypass_layer_sizes[i]
        top_bypass_layer = prev_bypass_layer

        if num_bypass_layers > 0:
          # task_layer has shape [None, layer_sizes[-1] + bypass_layer_sizes[-1]]
          task_layer = tf.concat(1, [top_multitask_layer, top_bypass_layer])
          task_layer_size = layer_sizes[-1] + bypass_layer_sizes[-1]
        else:
          task_layer = top_multitask_layer
          task_layer_size = layer_sizes[-1]
        ########################################################## DEBUG
        print("Adding output weights of shape %s"
              % str([task_layer_size, 1]))
        ########################################################## DEBUG
        #################################################### DEBUG
        print("task_layer_size")
        print(task_layer_size)
        #################################################### DEBUG
        output.append(tf.squeeze(
            model_ops.fully_connected_layer(
                tensor=task_layer,
                size=task_layer_size,
                weight_init=tf.truncated_normal(
                    shape=[task_layer_size, 1],
                    stddev=weight_init_stddevs[-1]),
                bias_init=tf.constant(value=bias_init_consts[-1],
                                      shape=[1]))))
      return output

  def construct_feed_dict(self, X_b, y_b=None, w_b=None, ids_b=None):
    """Construct a feed dictionary from minibatch data.

    TODO(rbharath): ids_b is not used here. Can we remove it?

    Args:
      X_b: np.ndarray of shape (batch_size, num_features)
      y_b: np.ndarray of shape (batch_size, num_tasks)
      w_b: np.ndarray of shape (batch_size, num_tasks)
      ids_b: List of length (batch_size) with datapoint identifiers.
    """ 
    orig_dict = {}
    orig_dict["mol_features"] = X_b
    for task in range(self.n_tasks):
      if y_b is not None:
        orig_dict["labels_%d" % task] = y_b[:, task]
      else:
        # Dummy placeholders
        orig_dict["labels_%d" % task] = np.squeeze(
            np.zeros((self.batch_size,)))
      if w_b is not None:
        orig_dict["weights_%d" % task] = w_b[:, task]
      else:
        # Dummy placeholders
        orig_dict["weights_%d" % task] = np.ones(
            (self.batch_size,)) 
    return TensorflowGraph.get_feed_dict(orig_dict)
+38 −16
Original line number Diff line number Diff line
@@ -26,6 +26,7 @@ from deepchem.models.keras_models.fcnet import MultiTaskDNN
from deepchem.models.tensorflow_models import TensorflowModel
from deepchem.models.tensorflow_models.fcnet import TensorflowMultiTaskRegressor
from deepchem.models.tensorflow_models.fcnet import TensorflowMultiTaskClassifier
from deepchem.models.tensorflow_models.robust_multitask import RobustMultitaskRegressor
from deepchem.models.multitask import SingletaskToMultitask
import tensorflow as tf
from keras import backend as K
@@ -580,22 +581,6 @@ class TestOverfitAPI(TestAPI):
  
    dataset = NumpyDataset(X, y, w, ids)

    model_params = {
      "layer_sizes": [1000],
      "dropouts": [.0],
      "learning_rate": 0.0003,
      "momentum": .9,
      "batch_size": n_samples,
      "num_regression_tasks": n_tasks,
      "num_classes": n_classes,
      "num_features": n_features,
      "weight_init_stddevs": [.1],
      "bias_init_consts": [1.],
      "nb_epoch": 100,
      "penalty": 0.0,
      "optimizer": "adam"
    }

    verbosity = "high"
    regression_metric = Metric(metrics.mean_squared_error, verbosity=verbosity,
                               task_averager=np.mean, mode="regression")
@@ -615,3 +600,40 @@ class TestOverfitAPI(TestAPI):
    scores = evaluator.compute_model_performance([regression_metric])

    assert scores[regression_metric.name] < .1

  def test_tf_robust_multitask_regression_overfit(self):
    """Test tf robust multitask overfits tiny data."""
    n_tasks = 10
    n_samples = 10
    n_features = 3
    n_classes = 2
    
    # Generate dummy dataset
    np.random.seed(123)
    ids = np.arange(n_samples)
    X = np.random.rand(n_samples, n_features)
    y = np.zeros((n_samples, n_tasks))
    w = np.ones((n_samples, n_tasks))
  
    dataset = NumpyDataset(X, y, w, ids)

    verbosity = "high"
    regression_metric = Metric(metrics.mean_squared_error, verbosity=verbosity,
                               task_averager=np.mean, mode="regression")
    tensorflow_model = RobustMultitaskRegressor(
        n_tasks, n_features, self.model_dir, layer_sizes=[50],
        bypass_layer_sizes=[10], dropouts=[0.],
        learning_rate=0.003, weight_init_stddevs=[.1],
        batch_size=n_samples, verbosity=verbosity)
    model = TensorflowModel(tensorflow_model, self.model_dir)

    # Fit trained model
    model.fit(dataset, nb_epoch=25)
    model.save()

    # Eval model on train
    transformers = []
    evaluator = Evaluator(model, dataset, transformers, verbosity=verbosity)
    scores = evaluator.compute_model_performance([regression_metric])

    assert scores[regression_metric.name] < .15