title: Sklearn error : predict(x,y) takes 2 positional arguments but 3 were given
body: <p>I am working on building a multivariate regression analysis on sklearn , I did a thorough look at the documentation. When I run the <code>predict()</code> function I get the error :  <code>predict()</code> takes 2 positional arguments but 3 were given</p>
  
  <p>X is a data frame , y is column; I have tried to convert the data frame to array / matrix but still get the error.</p>
  
  <p>Have added a snippet showing the x and y arrays.</p>
  
  <pre><code>reg.coef_
  reg.predict(x,y)
  
  x_train=train.drop('y-variable',axis =1)
  y_train=train['y-variable']
  
  x_test=test.drop('y-variable',axis =1)
  y_test=test['y-variable']
  
  
  x=x_test.as_matrix()
  y=y_test.as_matrix()
  
  reg = linear_model.LinearRegression()
  reg.fit(x_train,y_train)
  
  reg.predict(x,y)
  </code></pre>