Question

我用scikit-learn 获得了掌握机器学习的副本，我开始研究它。但是，似乎很多代码现在已经过时了。

本书中的第一个代码段，

import matplotlib.pyplot as plt X = [[6], [8], [10], [14], [18]] y = [[7], [9], [13], [17.5], [18]] plt.figure() plt.title('Pizza price plotted against diameter') plt.xlabel('Diameter in inches') plt.ylabel('Price in dollars') plt.plot(X, y, 'k.') plt.axis([0, 25, 0, 25]) plt.grid(True) plt.show()

跑得很好。但是，当我转到第二个时：

from sklearn.linear_model import LinearRegression # Training data X = [[6], [8], [10], [14], [18]] y = [[7], [9], [13], [17.5], [18]] # Create and fit the model model = LinearRegression() model.fit(X, y) print 'A 12" pizza should cost: $%.2f' % model.predict([12])[0]

它给了我一个错误：

A 12-inch pizza should cost: $%.2f /home/dave/anaconda3/lib/python3.5/site-packages/sklearn/utils/validation.py:386: DeprecationWarning: Passing 1d arrays as data is deprecated in 0.17 and willraise ValueError in 0.19. Reshape your data either using X.reshape(-1, 1) if your data has a single feature or X.reshape(1, -1) if it contains a single sample. DeprecationWarning) Traceback (most recent call last): File "002----Chapter2-B.py", line 11, in <module> print ("A 12-inch pizza should cost: $%.2f") % model.predict([12])[0] TypeError: unsupported operand type(s) for %: 'NoneType' and 'float'

当应给我这个时：

A 12" pizza should cost: $13.68

有没有解决这个问题？

Answer 1

尝试以下方法：

print ("A 12-inch pizza should cost: $%.2f" % model.predict(np.array([12]).reshape(1, -1)[0]))

我使用reshape(1,-1)将2d数组传递给predict函数。

Answer 2

以下是代码：

print('A ' + diameter + ' inch pizza should cost: $%.2f' % model.predict([d] [0]))

documentation pages提供了有关predict方法的更多详细信息：

sklearn.svm.libsvm.predict()

参数：

X : array-like, dtype=float, size=[n_samples, n_features]

Scikit-learn教程给我一个折旧错误，如何更新？

2 个答案: