title: AttributeError: 'numpy.ndarray' object has no attribute 'lower' fitting logistic model data
body: <p>I am running this code:</p>
  
  <pre><code>from sklearn import cross_validation
  import numpy as np
  import sys
  import pandas as pd
  import matplotlib.pyplot as plt
  from sklearn import datasets, svm, metrics
  
  digits = datasets.load_digits()
  
  X_train, X_test, y_train, y_test = cross_validation.train_test_split(
  digits.data, digits.target, test_size=0.4, random_state=0)
  
  clf = linear_model.LogisticRegression(X_train, y_train) 
  clf.fit(X_train, y_train)
  </code></pre>
  
  <p>I am getting this error:</p>
  
  <blockquote>
    <p>AttributeError: 'numpy.ndarray' object has no attribute 'lower'</p>
  </blockquote>
  
  <p>How can make the logistic model fit?</p>