def testWalsSolverLhs(self):
   sparse_block = SparseBlock3x3()
   with self.test_session():
     [lhs_tensor,
      rhs_matrix] = gen_factorization_ops.wals_compute_partial_lhs_and_rhs(
          self._column_factors, self._column_weights, self._unobserved_weights,
          self._row_weights, sparse_block.indices, sparse_block.values,
          sparse_block.dense_shape[0], False)
     self.assertAllClose(lhs_tensor.eval(), [[
         [0.014800, 0.017000, 0.019200],
         [0.017000, 0.019600, 0.022200],
         [0.019200, 0.022200, 0.025200],
     ], [
         [0.0064000, 0.0080000, 0.0096000],
         [0.0080000, 0.0100000, 0.0120000],
         [0.0096000, 0.0120000, 0.0144000],
     ], [
         [0.0099000, 0.0126000, 0.0153000],
         [0.0126000, 0.0162000, 0.0198000],
         [0.0153000, 0.0198000, 0.0243000],
     ], [
         [0.058800, 0.067200, 0.075600],
         [0.067200, 0.076800, 0.086400],
         [0.075600, 0.086400, 0.097200],
     ]])
     self.assertAllClose(rhs_matrix.eval(), [[0.019300, 0.023000, 0.026700],
                                             [0.061600, 0.077000, 0.092400],
                                             [0.160400, 0.220000, 0.279600],
                                             [0.492800, 0.563200, 0.633600]])
Exemplo n.º 2
0
  def _process_input_helper(self,
                            update_row_factors,
                            sp_input=None,
                            transpose_input=False,
                            row_weights=None):
    """Creates the graph for processing a sparse slice of input.

    Args:
      update_row_factors: if True, update or project the row_factors, else
        update or project the column factors.
      sp_input: Please refer to comments for update_row_factors,
        update_col_factors, project_row_factors, and project_col_factors for
        restrictions.
      transpose_input: If True, the input is logically transposed and then the
        corresponding rows/columns of the transposed input are updated.
      row_weights: If not None, this is the row/column weights to be used for
        the update or projection. If None, use the corresponding weights from
        the model. Note that the feature (column/row) weights will be
        determined by the model. When not None, it can either be a scalar or
        a rank-1 tensor with the same number of elements as the number of rows
        of columns to be updated/projected.

    Returns:
      A tuple consisting of the following elements:
      new_values: New values for the row/column factors.
      update_op: An op that assigns the newly computed values to the row/column
        factors.
      unregularized_loss: A tensor (scalar) that contains the normalized
        minibatch loss corresponding to sp_input, without the regularization
        term. Add the regularization term below to yield the loss.
      regularization: A tensor (scalar) that contains the normalized
        regularization term for the minibatch loss corresponding to sp_input.
      sum_weights: The sum of the weights corresponding to sp_input. This
        can be used with unregularized loss to calculate the root weighted
        squared error.
    """
    assert isinstance(sp_input, sparse_tensor.SparseTensor)

    if update_row_factors:
      left = self._row_factors
      right_factors = self._col_factors_cache
      row_wt = self._row_wt_cache
      col_wt = self._col_wt_cache
      total_rows = self._input_rows
      total_cols = self._input_cols
      sharding_func = WALSModel._get_sharding_func(self._input_rows,
                                                   self._num_row_shards)
      gramian = self._col_gramian_cache
    else:
      left = self._col_factors
      right_factors = self._row_factors_cache
      row_wt = self._col_wt_cache
      col_wt = self._row_wt_cache
      total_rows = self._input_cols
      total_cols = self._input_rows
      sharding_func = WALSModel._get_sharding_func(self._input_cols,
                                                   self._num_col_shards)
      gramian = self._row_gramian_cache
      transpose_input = not transpose_input

    # Note that the row indices of sp_input are based on the original full input
    # Here we reindex the rows and give them contiguous ids starting at 0.
    # We use tf.unique to achieve this reindexing. Note that this is done so
    # that the downstream kernel can assume that the input is "dense" along the
    # row dimension.
    row_ids, col_ids = array_ops.split(
        value=sp_input.indices, num_or_size_splits=2, axis=1)
    update_row_indices, all_row_ids = array_ops.unique(row_ids[:, 0])
    update_col_indices, all_col_ids = array_ops.unique(col_ids[:, 0])
    col_ids = array_ops.expand_dims(math_ops.cast(all_col_ids, dtypes.int64), 1)
    row_ids = array_ops.expand_dims(math_ops.cast(all_row_ids, dtypes.int64), 1)

    if transpose_input:
      update_indices = update_col_indices
      row_shape = [
          math_ops.cast(array_ops.shape(update_row_indices)[0], dtypes.int64)
      ]
      gather_indices = update_row_indices
    else:
      update_indices = update_row_indices
      row_shape = [
          math_ops.cast(array_ops.shape(update_col_indices)[0], dtypes.int64)
      ]
      gather_indices = update_col_indices

    num_rows = math_ops.cast(array_ops.shape(update_indices)[0], dtypes.int64)
    col_shape = [num_rows]
    right = embedding_ops.embedding_lookup(
        right_factors, gather_indices, partition_strategy="div")
    new_sp_indices = array_ops.concat([row_ids, col_ids], 1)
    new_sp_shape = (array_ops.concat([row_shape, col_shape], 0)
                    if transpose_input else
                    array_ops.concat([col_shape, row_shape], 0))
    new_sp_input = sparse_tensor.SparseTensor(
        indices=new_sp_indices,
        values=sp_input.values,
        dense_shape=new_sp_shape)

    # Compute lhs and rhs of the normal equations
    total_lhs = (self._unobserved_weight * gramian)
    if self._regularization_matrix is not None:
      total_lhs += self._regularization_matrix
    if self._row_weights is None:
      # Special case of ALS. Use a much simpler update rule.
      total_rhs = (
          self._unobserved_weight * sparse_ops.sparse_tensor_dense_matmul(
              new_sp_input, right, adjoint_a=transpose_input))
      # TODO (rmlarsen): handle transposing in tf.matrix_solve instead of id:1138
      # https://github.com/imdone/tensorflow/issues/1139
      # transposing explicitly.
      # TODO (rmlarsen): multi-thread tf.matrix_solve. id:1249
      # https://github.com/imdone/tensorflow/issues/1250
      new_left_values = array_ops.transpose(
          linalg_ops.matrix_solve(total_lhs, array_ops.transpose(total_rhs)))
    else:
      if row_weights is None:
        # TODO (yifanchen): Add special handling for single shard without using id:845
        # https://github.com/imdone/tensorflow/issues/846
        # embedding_lookup and perform benchmarks for those cases. Same for
        # col_weights lookup below.
        row_weights_slice = embedding_ops.embedding_lookup(
            row_wt, update_indices, partition_strategy="div")
      else:
        num_indices = array_ops.shape(update_indices)[0]
        with ops.control_dependencies(
            [check_ops.assert_less_equal(array_ops.rank(row_weights), 1)]):
          row_weights_slice = control_flow_ops.cond(
              math_ops.equal(array_ops.rank(row_weights), 0),
              lambda: (array_ops.ones([num_indices]) * row_weights),
              lambda: math_ops.cast(row_weights, dtypes.float32))

      col_weights = embedding_ops.embedding_lookup(
          col_wt, gather_indices, partition_strategy="div")
      partial_lhs, total_rhs = (
          gen_factorization_ops.wals_compute_partial_lhs_and_rhs(
              right,
              col_weights,
              self._unobserved_weight,
              row_weights_slice,
              new_sp_input.indices,
              new_sp_input.values,
              num_rows,
              transpose_input,
              name="wals_compute_partial_lhs_rhs"))
      total_lhs = array_ops.expand_dims(total_lhs, 0) + partial_lhs
      total_rhs = array_ops.expand_dims(total_rhs, -1)
      new_left_values = array_ops.squeeze(
          linalg_ops.matrix_solve(total_lhs, total_rhs), [2])

    update_op_name = "row_update" if update_row_factors else "col_update"
    update_op = self.scatter_update(
        left,
        update_indices,
        new_left_values,
        sharding_func,
        name=update_op_name)

    # Create the loss subgraph
    loss_sp_input = (sparse_ops.sparse_transpose(new_sp_input)
                     if transpose_input else new_sp_input)
    # sp_approx is the low rank estimate of the input matrix, formed by
    # computing the product <\\(u_i, v_j\\)> for (i, j) in loss_sp_input.indices.
    sp_approx_vals = gen_factorization_ops.masked_matmul(
        new_left_values,
        right,
        loss_sp_input.indices,
        transpose_a=False,
        transpose_b=True)
    sp_approx = sparse_tensor.SparseTensor(
        loss_sp_input.indices, sp_approx_vals, loss_sp_input.dense_shape)
    sp_approx_sq = math_ops.square(sp_approx)
    sp_residual = sparse_ops.sparse_add(loss_sp_input, sp_approx * (-1))
    sp_residual_sq = math_ops.square(sp_residual)
    row_wt_mat = (constant_op.constant(0.)
                  if self._row_weights is None else array_ops.expand_dims(
                      row_weights_slice, 1))
    col_wt_mat = (constant_op.constant(0.)
                  if self._col_weights is None else array_ops.expand_dims(
                      col_weights, 0))

    # We return the normalized loss
    partial_row_gramian = math_ops.matmul(
        new_left_values, new_left_values, transpose_a=True)
    normalization_factor = total_rows / math_ops.cast(num_rows, dtypes.float32)

    unregularized_loss = (
        self._unobserved_weight * (  # pyformat line break
            sparse_ops.sparse_reduce_sum(sp_residual_sq) -  # pyformat break
            sparse_ops.sparse_reduce_sum(sp_approx_sq) +  # pyformat break
            math_ops.trace(math_ops.matmul(partial_row_gramian, gramian))) +
        sparse_ops.sparse_reduce_sum(row_wt_mat * (sp_residual_sq * col_wt_mat))
    ) * normalization_factor

    if self._regularization is not None:
      regularization = self._regularization * (
          math_ops.trace(partial_row_gramian) * normalization_factor +
          math_ops.trace(gramian))
    else:
      regularization = constant_op.constant(0.)

    sum_weights = self._unobserved_weight * math_ops.cast(
        total_rows * total_cols, dtypes.float32)
    if self._row_weights is not None and self._col_weights is not None:
      ones = sparse_tensor.SparseTensor(
          indices=loss_sp_input.indices,
          values=array_ops.ones(array_ops.shape(loss_sp_input.values)),
          dense_shape=loss_sp_input.dense_shape)
      sum_weights += sparse_ops.sparse_reduce_sum(row_wt_mat * (
          ones * col_wt_mat)) * normalization_factor

    return (new_left_values, update_op, unregularized_loss, regularization,
            sum_weights)
Exemplo n.º 3
0
  def _process_input_helper(self,
                            update_row_factors,
                            sp_input=None,
                            transpose_input=False,
                            row_weights=None):
    """Creates the graph for processing a sparse slice of input.

    Args:
      update_row_factors: if True, update or project the row_factors, else
        update or project the column factors.
      sp_input: Please refer to comments for update_row_factors,
        update_col_factors, project_row_factors, and project_col_factors for
        restrictions.
      transpose_input: If True, the input is logically transposed and then the
        corresponding rows/columns of the transposed input are updated.
      row_weights: If not None, this is the row/column weights to be used for
        the update or projection. If None, use the corresponding weights from
        the model. Note that the feature (column/row) weights will be
        determined by the model. When not None, it can either be a scalar or
        a rank-1 tensor with the same number of elements as the number of rows
        of columns to be updated/projected.

    Returns:
      A tuple consisting of the following elements:
      new_values: New values for the row/column factors.
      update_op: An op that assigns the newly computed values to the row/column
        factors.
      unregularized_loss: A tensor (scalar) that contains the normalized
        minibatch loss corresponding to sp_input, without the regularization
        term. Add the regularization term below to yield the loss.
      regularization: A tensor (scalar) that contains the normalized
        regularization term for the minibatch loss corresponding to sp_input.
      sum_weights: The sum of the weights corresponding to sp_input. This
        can be used with unregularized loss to caluclate the root weighted
        squared error.
    """
    assert isinstance(sp_input, sparse_tensor.SparseTensor)

    if update_row_factors:
      left = self._row_factors
      right_factors = self._col_factors_cache
      row_wt = self._row_wt_cache
      col_wt = self._col_wt_cache
      total_rows = self._input_rows
      total_cols = self._input_cols
      sharding_func = WALSModel._get_sharding_func(self._input_rows,
                                                   self._num_row_shards)
      gramian = self._col_gramian_cache
    else:
      left = self._col_factors
      right_factors = self._row_factors_cache
      row_wt = self._col_wt_cache
      col_wt = self._row_wt_cache
      total_rows = self._input_cols
      total_cols = self._input_rows
      sharding_func = WALSModel._get_sharding_func(self._input_cols,
                                                   self._num_col_shards)
      gramian = self._row_gramian_cache
      transpose_input = not transpose_input

    # Note that the row indices of sp_input are based on the original full input
    # Here we reindex the rows and give them contiguous ids starting at 0.
    # We use tf.unique to achieve this reindexing. Note that this is done so
    # that the downstream kernel can assume that the input is "dense" along the
    # row dimension.
    row_ids, col_ids = array_ops.split(
        value=sp_input.indices, num_or_size_splits=2, axis=1)
    update_row_indices, all_row_ids = array_ops.unique(row_ids[:, 0])
    update_col_indices, all_col_ids = array_ops.unique(col_ids[:, 0])
    col_ids = array_ops.expand_dims(math_ops.cast(all_col_ids, dtypes.int64), 1)
    row_ids = array_ops.expand_dims(math_ops.cast(all_row_ids, dtypes.int64), 1)

    if transpose_input:
      update_indices = update_col_indices
      row_shape = [
          math_ops.cast(array_ops.shape(update_row_indices)[0], dtypes.int64)
      ]
      gather_indices = update_row_indices
    else:
      update_indices = update_row_indices
      row_shape = [
          math_ops.cast(array_ops.shape(update_col_indices)[0], dtypes.int64)
      ]
      gather_indices = update_col_indices

    num_rows = math_ops.cast(array_ops.shape(update_indices)[0], dtypes.int64)
    col_shape = [num_rows]
    right = embedding_ops.embedding_lookup(
        right_factors, gather_indices, partition_strategy="div")
    new_sp_indices = array_ops.concat([row_ids, col_ids], 1)
    new_sp_shape = (array_ops.concat([row_shape, col_shape], 0)
                    if transpose_input else
                    array_ops.concat([col_shape, row_shape], 0))
    new_sp_input = sparse_tensor.SparseTensor(
        indices=new_sp_indices,
        values=sp_input.values,
        dense_shape=new_sp_shape)

    # Compute lhs and rhs of the normal equations
    total_lhs = (self._unobserved_weight * gramian)
    if self._regularization_matrix is not None:
      total_lhs += self._regularization_matrix
    if self._row_weights is None:
      # Special case of ALS. Use a much simpler update rule.
      total_rhs = (
          self._unobserved_weight * sparse_ops.sparse_tensor_dense_matmul(
              new_sp_input, right, adjoint_a=transpose_input))
      # TODO(rmlarsen): handle transposing in tf.matrix_solve instead of
      # transposing explicitly.
      # TODO(rmlarsen): multi-thread tf.matrix_solve.
      new_left_values = array_ops.transpose(
          linalg_ops.matrix_solve(total_lhs, array_ops.transpose(total_rhs)))
    else:
      if row_weights is None:
        # TODO(yifanchen): Add special handling for single shard without using
        # embedding_lookup and perform benchmarks for those cases. Same for
        # col_weights lookup below.
        row_weights_slice = embedding_ops.embedding_lookup(
            row_wt, update_indices, partition_strategy="div")
      else:
        num_indices = array_ops.shape(update_indices)[0]
        with ops.control_dependencies(
            [check_ops.assert_less_equal(array_ops.rank(row_weights), 1)]):
          row_weights_slice = control_flow_ops.cond(
              math_ops.equal(array_ops.rank(row_weights), 0),
              lambda: (array_ops.ones([num_indices]) * row_weights),
              lambda: math_ops.cast(row_weights, dtypes.float32))

      col_weights = embedding_ops.embedding_lookup(
          col_wt, gather_indices, partition_strategy="div")
      partial_lhs, total_rhs = (
          gen_factorization_ops.wals_compute_partial_lhs_and_rhs(
              right,
              col_weights,
              self._unobserved_weight,
              row_weights_slice,
              new_sp_input.indices,
              new_sp_input.values,
              num_rows,
              transpose_input,
              name="wals_compute_partial_lhs_rhs"))
      total_lhs = array_ops.expand_dims(total_lhs, 0) + partial_lhs
      total_rhs = array_ops.expand_dims(total_rhs, -1)
      new_left_values = array_ops.squeeze(
          linalg_ops.matrix_solve(total_lhs, total_rhs), [2])

    update_op_name = "row_update" if update_row_factors else "col_update"
    update_op = self.scatter_update(
        left,
        update_indices,
        new_left_values,
        sharding_func,
        name=update_op_name)

    # Create the loss subgraph
    loss_sp_input = (sparse_ops.sparse_transpose(new_sp_input)
                     if transpose_input else new_sp_input)
    # sp_approx is the low rank estimate of the input matrix, formed by
    # computing the product <u_i, v_j> for (i, j) in loss_sp_input.indices.
    sp_approx_vals = gen_factorization_ops.masked_matmul(
        new_left_values,
        right,
        loss_sp_input.indices,
        transpose_a=False,
        transpose_b=True)
    sp_approx = sparse_tensor.SparseTensor(
        loss_sp_input.indices, sp_approx_vals, loss_sp_input.dense_shape)
    sp_approx_sq = math_ops.square(sp_approx)
    sp_residual = sparse_ops.sparse_add(loss_sp_input, sp_approx * (-1))
    sp_residual_sq = math_ops.square(sp_residual)
    row_wt_mat = (constant_op.constant(0.)
                  if self._row_weights is None else array_ops.expand_dims(
                      row_weights_slice, 1))
    col_wt_mat = (constant_op.constant(0.)
                  if self._col_weights is None else array_ops.expand_dims(
                      col_weights, 0))

    # We return the normalized loss
    partial_row_gramian = math_ops.matmul(
        new_left_values, new_left_values, transpose_a=True)
    normalization_factor = total_rows / math_ops.cast(num_rows, dtypes.float32)

    unregularized_loss = (
        self._unobserved_weight * (  # pyformat line break
            sparse_ops.sparse_reduce_sum(sp_residual_sq) -  # pyformat break
            sparse_ops.sparse_reduce_sum(sp_approx_sq) +  # pyformat break
            math_ops.trace(math_ops.matmul(partial_row_gramian, gramian))) +
        sparse_ops.sparse_reduce_sum(row_wt_mat * (sp_residual_sq * col_wt_mat))
    ) * normalization_factor

    if self._regularization is not None:
      regularization = self._regularization * (
          math_ops.trace(partial_row_gramian) * normalization_factor +
          math_ops.trace(gramian))
    else:
      regularization = constant_op.constant(0.)

    sum_weights = self._unobserved_weight * math_ops.cast(
        total_rows * total_cols, dtypes.float32)
    if self._row_weights is not None and self._col_weights is not None:
      ones = sparse_tensor.SparseTensor(
          indices=loss_sp_input.indices,
          values=array_ops.ones(array_ops.shape(loss_sp_input.values)),
          dense_shape=loss_sp_input.dense_shape)
      sum_weights += sparse_ops.sparse_reduce_sum(row_wt_mat * (
          ones * col_wt_mat)) * normalization_factor

    return (new_left_values, update_op, unregularized_loss, regularization,
            sum_weights)