TypeError：不支持的操作数类型为 - ：'numpy.ndarray'和'numpy.ndarray'

Question

我想从我的sci-kit学习模型中预测y_train_actual的均方根误差与原始值salaries 。

问题：但与mean_squared_error(y_train_actual, salaries)，我收到错误TypeError: unsupported operand type(s) for -: 'numpy.ndarray' and 'numpy.ndarray'。作为第二个参数使用list(salaries)而不是salaries会产生相同的错误。

随着mean_squared_error(y_train_actual, y_valid_actual)我收到错误Found array with dim 40663. Expected 244768

我怎么能转换为正确的数组类型sklearn.netrucs.mean_squared_error()？

代码

from sklearn.metrics import mean_squared_error 

y_train_actual = [ np.exp(float(row)) for row in y_train ] 
print mean_squared_error(y_train_actual, salaries) 

错误

TypeError         Traceback (most recent call last) 
<ipython-input-144-b6d4557ba9c5> in <module>() 
     3 y_valid_actual = [ np.exp(float(row)) for row in y_valid ] 
     4 
----> 5 print mean_squared_error(y_train_actual, salaries) 
     6 print mean_squared_error(y_train_actual, y_valid_actual) 

C:\Python27\lib\site-packages\sklearn\metrics\metrics.pyc in mean_squared_error(y_true, y_pred) 
    1462  """ 
    1463  y_true, y_pred = check_arrays(y_true, y_pred) 
-> 1464  return np.mean((y_pred - y_true) ** 2) 
    1465 
    1466 

TypeError: unsupported operand type(s) for -: 'numpy.ndarray' and 'numpy.ndarray' 

代码

y_train_actual = [ np.exp(float(row)) for row in y_train ] 
y_valid_actual = [ np.exp(float(row)) for row in y_valid ] 

print mean_squared_error(y_train_actual, y_valid_actual) 

错误

ValueError        Traceback (most recent call last) 
<ipython-input-146-7fcd0367c6f1> in <module>() 
     4 
     5 #print mean_squared_error(y_train_actual, salaries) 
----> 6 print mean_squared_error(y_train_actual, y_valid_actual) 

C:\Python27\lib\site-packages\sklearn\metrics\metrics.pyc in mean_squared_error(y_true, y_pred) 
    1461 
    1462  """ 
-> 1463  y_true, y_pred = check_arrays(y_true, y_pred) 
    1464  return np.mean((y_pred - y_true) ** 2) 
    1465 

C:\Python27\lib\site-packages\sklearn\utils\validation.pyc in check_arrays(*arrays, **options) 
    191   if size != n_samples: 
    192    raise ValueError("Found array with dim %d. Expected %d" 
--> 193        % (size, n_samples)) 
    194 
    195   if not allow_lists or hasattr(array, "shape"): 

ValueError: Found array with dim 40663. Expected 244768 

代码

print type(y_train) 
print type(y_train_actual) 
print type(salaries) 

结果

<type 'list'> 
<type 'list'> 
<type 'tuple'> 

---

打印y_train [：10]

个

[10.126631103850338, 10.308952660644293, 10.308952660644293, 10.221941283654663, 10.126631103850338, 10.126631103850338, 11.225243392518447, 9.9987977323404529, 10.043249494911286, 11.350406535472453]

打印薪金[：10]

('25000', '30000', '30000', '27500', '25000', '25000', '75000', '22000', '23000', '85000')

打印列表（工资）[：10]

['25000', '30000', '30000', '27500', '25000', '25000', '75000', '22000', '23000', '85000']

打印文件N（y_train）

244768 

打印LEN（工资）

244768 

Answer 1

的TypeError问题从薪金是字符串的列表而y_train_actual是浮筒的列表茎。那些不能被减去。

对于你的第二个错误，你应该确保两个数组的大小相同，否则它不能减去它们。