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使用scikit-learn python的线性SVM时的ValueError

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我目前正在进行ODP文档的大规模分层文本分类 . 提供给我的数据集采用libSVM格式 . 我正在尝试运行python scikit的线性内核SVM - 学习开发模型 . 以下是培训样本的样本数据:

29 9454:1 11742:1 18884:14 26840:1 35147:1 52782:1 72083:1 73244:1 78945:1 79913:1 79986:1 86710:3 117286:1 139820:1 142458:1 146315:1 151005:2 161454:3 172237:1 1091130:1 1113562:1 1133451:1 1139046:1 1157534:1 1180618:2 1182024:1 1187711:1 1194345:3 

33 2474:1 8152:1 19529:2 35038:1 48104:1 59738:1 61854:3 67943:1 74093:1 78945:1 88558:1 90848:1 97087:1 113284:16 118917:1 122375:1 124939:1

以下是我用于构建线性SVM模型的代码

from sklearn.datasets import load_svmlight_file
from sklearn import svm
X_train, y_train = load_svmlight_file("/path-to-file/train.txt")
X_test, y_test = load_svmlight_file("/path-to-file/test.txt")
clf = svm.SVC(kernel='linear')
clf.fit(X_train, y_train)
print clf.score(X_test,y_test)

运行clf.score()时,我收到以下错误:

---------------------------------------------------------------------------
ValueError                                Traceback (most recent call last)
<ipython-input-6-b285fbfb3efe> in <module>()
      1 start_time = time.time()
----> 2 print clf.score(X_test,y_test)
      3 print time.time() - start_time, "seconds"

/Users/abc/anaconda/lib/python2.7/site-packages/sklearn/base.pyc in score(self, X, y)
    292         """
    293         from .metrics import accuracy_score
--> 294         return accuracy_score(y, self.predict(X))
    295 
    296 

/Users/abc/anaconda/lib/python2.7/site-packages/sklearn/svm/base.pyc in predict(self, X)
    464             Class labels for samples in X.
    465         """
--> 466         y = super(BaseSVC, self).predict(X)
    467         return self.classes_.take(y.astype(np.int))
    468 

/Users/abc/anaconda/lib/python2.7/site-packages/sklearn/svm/base.pyc in predict(self, X)
    280         y_pred : array, shape (n_samples,)
    281         """
--> 282         X = self._validate_for_predict(X)
    283         predict = self._sparse_predict if self._sparse else self._dense_predict
    284         return predict(X)

/Users/abc/anaconda/lib/python2.7/site-packages/sklearn/svm/base.pyc in _validate_for_predict(self, X)
    402             raise ValueError("X.shape[1] = %d should be equal to %d, "
    403                              "the number of features at training time" %
--> 404                              (n_features, self.shape_fit_[1]))
    405         return X
    406 

ValueError: X.shape[1] = 1199847 should be equal to 1199830, the number of features at training time

有人可以让我知道这个代码或我拥有的数据有什么问题吗?提前致谢

下面附有X_train,y_train,X_test和y_test的值:

X_train:

(0, 9453)         1.0
  (0, 11741)    1.0
  (0, 18883)    14.0
  (0, 26839)    1.0
  (0, 35146)    1.0
  (0, 52781)    1.0
  (0, 72082)    1.0
  (0, 73243)    1.0
  (0, 78944)    1.0
  (0, 79912)    1.0
  (0, 79985)    1.0
  (0, 86709)    3.0
  (0, 117285)   1.0
  (0, 139819)   1.0
  (0, 142457)   1.0
  (0, 146314)   1.0
  (0, 151004)   2.0
  (0, 161453)   3.0
  (0, 172236)   1.0
  (0, 187531)   2.0
  (0, 202462)   1.0
  (0, 210417)   1.0
  (0, 250581)   1.0
  (0, 251689)   1.0
  (0, 296384)   2.0
  : :
  (4462, 735469)    1.0
  (4462, 737059)    15.0
  (4462, 740127)    1.0
  (4462, 743798)    1.0
  (4462, 766063)    1.0
  (4462, 778958)    2.0
  (4462, 784004)    4.0
  (4462, 837264)    2.0
  (4462, 839095)    22.0
  (4462, 844735)    6.0
  (4462, 859721)    2.0
  (4462, 875267)    1.0
  (4462, 910761)    1.0
  (4462, 931244)    1.0
  (4462, 945069)    6.0
  (4462, 948728)    1.0
  (4462, 948850)    2.0
  (4462, 957682)    1.0
  (4462, 975170)    1.0
  (4462, 989192)    1.0
  (4462, 1014294)   1.0
  (4462, 1042424)   1.0
  (4462, 1049027)   1.0
  (4462, 1072931)   1.0
  (4462, 1145790)   1.0

y_train:

[  2.90000000e+01   3.30000000e+01   3.30000000e+01 ...,   1.65475000e+05
   1.65518000e+05   1.65518000e+05]

X_test:

(0, 18573)    1.0
  (0, 23501)    1.0
  (0, 29954)    1.0
  (0, 42112)    1.0
  (0, 46402)    1.0
  (0, 63041)    2.0
  (0, 67942)    2.0
  (0, 83522)    1.0
  (0, 88413)    2.0
  (0, 99454)    1.0
  (0, 126041)   1.0
  (0, 139819)   1.0
  (0, 142678)   1.0
  (0, 151004)   1.0
  (0, 166351)   2.0
  (0, 173794)   1.0
  (0, 192162)   3.0
  (0, 210417)   2.0
  (0, 254468)   1.0
  (0, 263895)   2.0
  (0, 277567)   1.0
  (0, 278419)   2.0
  (0, 279181)   2.0
  (0, 281319)   2.0
  (0, 298898)   1.0
  : :
  (1857, 1100504)   3.0
  (1857, 1103247)   1.0
  (1857, 1105578)   1.0
  (1857, 1108986)   2.0
  (1857, 1118486)   1.0
  (1857, 1120807)   9.0
  (1857, 1129243)   2.0
  (1857, 1131786)   1.0
  (1857, 1134029)   2.0
  (1857, 1134410)   5.0
  (1857, 1134494)   1.0
  (1857, 1139045)   25.0
  (1857, 1142239)   3.0
  (1857, 1142651)   1.0
  (1857, 1144787)   1.0
  (1857, 1151891)   1.0
  (1857, 1152094)   1.0
  (1857, 1157533)   1.0
  (1857, 1159376)   1.0
  (1857, 1178944)   1.0
  (1857, 1181310)   2.0
  (1857, 1182023)   1.0
  (1857, 1187098)   1.0
  (1857, 1194344)   2.0
  (1857, 1195819)   9.0

y_test:

[  2.90000000e+01   3.30000000e+01   1.56000000e+02 ...,   1.65434000e+05
   1.65475000e+05   1.65518000e+05]

4 回答

  • 0

    问题发现!!

    # -*- coding:utf-8 -*-
    
    • 该文件应使用utf-8进行编码

    • 应重新整形数据框对象 . 喜欢 X_train.values[4].reshape(1, -1)

  • 0

    在我的情况下,这可以通过删除已创建的模型来解决 . 如果您在训练期间使用了--fixed_model_name选项,则可能会发生这种情况 . 说训练数据或数据格式(在我的情况下,它是 - 数据和md到json)改变==>它创建模型没有任何问题但是当我们发布查询时rasa错误与此消息关闭 .

  • 7

    错误消息

    ValueError: X.shape[1] = 1199847 should be equal to 1199830, the number of features at training time
    

    解释说明:与用于训练模型的训练数据相比,测试数据中的特征数量不同 . 也就是说, X_train.shape[1] 不等于 X_test.shape[1] .

    你应该检查他们为什么不平等 .

    一种可能性是它们作为稀疏矩阵加载,并且load_svmlight_file推断出特征的数量 . 如果测试数据包含训练数据未见的特征,则生成的 X_test 可能具有更大的维度 . 要避免这种情况,可以通过传递参数 n_features 来指定 load_svmlight_file 中的要素数 .

  • 2

    您可以使用 n_features 选项 .

    X_train, y_train = load_svmlight_file("/path-to-file/train.txt")
    X_test, y_test = load_svmlight_file("/path-to-file/test.txt", n_features=X_train.shape[1])
    

    使用 load_svmlight_files 也可以解决此错误

    from sklearn.datasets import load_svmlight_files
    X_train, y_train, X_test, y_test = load_svmlight_files(['/path-to-file/train.txt', '/path-to-file/test.txt'])
    

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