Tensorflow error: "Tensor must be from the same graph as Tensor..."

Question

I am trying to train a simple binary logistic regression classifier using Tensorflow (version 0.9.0) in a very similar way to the beginner's tutorial and am encountering the following error when fitting the model:

ValueError: Tensor("centered_bias_weight:0", shape=(1,), dtype=float32_ref) must be from the same graph as Tensor("linear_14/BiasAdd:0", shape=(?, 1), dtype=float32).

Here is my code:

import tempfile
import tensorflow as tf
import pandas as pd

# Customized training data parsing
train_data = read_train_data()
feature_names = get_feature_names(train_data)
labels = get_labels(train_data)

# Construct dataframe from training data features
x_train = pd.DataFrame(train_data , columns=feature_names)
x_train["label"] = labels

y_train = tf.constant(labels)

# Create SparseColumn for each feature (assume all feature values are integers and either 0 or 1)
feature_cols = [ tf.contrib.layers.sparse_column_with_integerized_feature(f,2) for f in feature_names ]

# Create SparseTensor for each feature based on data
categorical_cols = { f: tf.SparseTensor(indices=[[i,0] for i in range(x_train[f].size)],
               values=x_train[f].values,
               shape=[x_train[f].size,1]) for f in feature_names }

# Initialize logistic regression model
model_dir = tempfile.mkdtemp()
model = tf.contrib.learn.LinearClassifier(feature_columns=feature_cols, model_dir=model_dir)

def eval_input_fun():
    return categorical_cols, y_train

# Fit the model - similarly to the tutorial
model.fit(input_fn=eval_input_fun, steps=200)

I feel like I'm missing something critical... maybe something that was assumed in the tutorial but wasn't explicitly mentioned?

Also, I get the following warning every time I call fit():

WARNING:tensorflow:create_partitioned_variables is deprecated.  Use tf.get_variable with a partitioner set, or tf.get_partitioned_variable_list, instead.

Answer 1

When you execute model.fit, the LinearClassifier is creating a separate tf.Graph based on the Ops contained in your eval_input_fun function. But, during the creation of this Graph, LinearClassifier doesn't have access to the definitions of categorical_cols and y_train you saved globally.

Solution: move all the Ops definitions (and their dependencies) inside eval_input_fun