实际上,为了简化代码,我决定使用带有Dataframe作为参数的函数,而不是编写两个相似的零件代码。如下所示:
from sklearn.neighbors import KNeighborsRegressor
from sklearn.metrics import mean_squared_error
train_one = split_one
test_one = split_two
train_two = split_two
test_two = split_one
def train_predict(train_arg, predict_arg):
knn = KNeighborsRegressor()
knn.fit(train_arg['accommodates'], train_arg['price'])
predict = knn.predict(predict_arg['accommodates'])
rmse = numpy.sqrt(mean_squared_error(predict_arg['price'], predict))
return rmse
iteration_one_rmse = train_predict(train_one, test_one)
iteration_two_rmse = train_predict(train_two, test_two)
avg_rmse = numpy.mean(iteration_one_rmse, iteration_two_rmse)
函数定义块中的参数可能不合适。但是,我无法弄清楚。感谢您的任何提示。 带有这样的错误通知:
ValueErrorTraceback (most recent call last)
<ipython-input-1-f3f78fcf6758> in <module>()
14 return rmse
15
---> 16 iteration_one_rmse = train_predict(train_one, test_one)
17 iteration_two_rmse = train_predict(train_two, test_two)
18
<ipython-input-1-f3f78fcf6758> in train_predict(train_arg, predict_arg)
9 def train_predict(train_arg, predict_arg):
10 knn = KNeighborsRegressor()
---> 11 knn.fit(train_arg['accommodates'], train_arg['price'])
12 predict = knn.predict(predict_arg['accommodates'])
13 rmse = numpy.sqrt(mean_squared_error(predict_arg['price'], predict))
/dataquest/system/env/python3/lib/python3.4/site-packages/sklearn/neighbors/base.py in fit(self, X, y)
739 """
740 if not isinstance(X, (KDTree, BallTree)):
--> 741 X, y = check_X_y(X, y, "csr", multi_output=True)
742 self._y = y
743 return self._fit(X)
/dataquest/system/env/python3/lib/python3.4/site-packages/sklearn/utils/validation.py in check_X_y(X, y, accept_sparse, dtype, order, copy, force_all_finite, ensure_2d, allow_nd, multi_output, ensure_min_samples, ensure_min_features, y_numeric, warn_on_dtype, estimator)
529 y = y.astype(np.float64)
530
--> 531 check_consistent_length(X, y)
532
533 return X, y
/dataquest/system/env/python3/lib/python3.4/site-packages/sklearn/utils/validation.py in check_consistent_length(*arrays)
179 if len(uniques) > 1:
180 raise ValueError("Found input variables with inconsistent numbers of"
--> 181 " samples: %r" % [int(l) for l in lengths])
182
183
ValueError: Found input variables with inconsistent numbers of samples: [1, 1862]
答案 0 :(得分:2)
如果train_arg
是一个数据帧,则train_arg['accomodates']
是一个序列,而train_arg[['accomodate']]
是一个数据帧(仅包含一个列)。
由于假定拟合和预测中使用的数据具有多列,所以函数将在pandas.DataFrame
上,而不会在pandas.Series
上。
为防止发生此错误,请确保您的数据(适合的第一个参数,而预测的仅参数)的类型为pandas.DataFrame
或numpy.ndarray
。
答案 1 :(得分:0)
事实上,我修改了如下代码。
def train_predict(train_arg, predict_arg):
knn = KNeighborsRegressor()
knn.fit(train_arg[['accommodates']], train_arg['price'])
predict = knn.predict(predict_arg[['accommodates']])
rmse = numpy.sqrt(mean_squared_error(predict_arg['price'], predict))
return rmse
请注意 train_arg[['accommodates']]
中的双括号。
添加双括号确实有效。但是我确实不明白原因。有任何提示吗?