title: Error when checking target: expected dense_2 to have shape (3,) but got array with shape (1,)
body: <p>I changed the data type but I could not resolve the error.</p>
  
  <p>I tried One-Hot Encoding but it doesn't work too.</p>
  
  <p>I don't know what's wrong:(</p>
  
  <pre><code>seed = 0
  np.random.seed(seed)
  tf.set_random_seed(seed)
  
  df = pd.read_csv('HW01_dataset_tae.txt', sep=',' ,header=None, names = ["Native", "Instructor", "Course", "Semester", "Class Size", "Evaluation"])
  
  dataset = df.values # dataframe to int64
  X = dataset[:,0:5] # attribute
  Y_Eva = dataset[:,5] # class 
  
  e = LabelEncoder()
  e.fit(Y_Eva)
  Y = e.transform(Y_Eva)
  
  K = 10 
  kFold = StratifiedKFold(n_splits=K, shuffle=True, random_state=seed) 
  
  accuracy = []
  
  for train_index, test_index in kFold.split(X,Y):
      model = Sequential() 
      model.add(Dense(16, input_dim=5, activation='relu')) 
      model.add(Dense(10, activation='relu')) 
      model.add(Dense(3, activation='softmax'))
      model.compile(loss='mean_squared_error', 
                optimizer='adam', 
                metrics=['accuracy'])
      model.fit(X[train_index], Y[train_index], epochs=100, batch_size=2)
  
  </code></pre>
  
  <p>the error ; Error when checking target: expected dense_2 to have shape (3,) but got array with shape (1,)</p>
  
  <p>is detected at here ; model.fit(X[train_index], Y[train_index], epochs=100, batch_size=2).</p>
  
  <p>What shout I do?</p>