Python：将 kmean.labels_ 添加到 Numpy 数组

Question

两个Numpy数组的大小分别是：

(406, 278)
(406,)

但是，附加 Numpy 数组时出错：

ValueError: all the input arrays must have same number of dimensions

代码：

y = numpy.array(kmeans.labels_,copy=True)
x = numpy.append(x, y, axis=1); #error
x = numpy.append(x, y, axis=0); #error

Answer 1

如错误所述，您正在尝试将一维数组附加到带有轴参数的二维数组，并且根据文档：

When axis is specified, values must have the correct shape.

您需要先将 y 整形为二维数组：

这两种方法都应该有效：

np.append(x, y[None, :], axis=0)
np.append(x, y.reshape(1,-1), axis=0)

Answer 2

When axis is specified, values must have the correct shape.

所以如果你想把向量y = [0 1 2]附加到矩阵x = [[0, 0],[1, 1],[2, 2]]和axis=1，首先你需要把y变成矩阵形式，然后转置它：

x = numpy.zeros((406,278))
y = numpy.zeros((406,))
x = numpy.append(x, numpy.transpose([y]), axis=1);
print(x.shape)   # gives (406,279)

Python: append kmean.labels_ to Numpy array