Numpy 位置列表型索引

def shuffle_indices(size):
    arr = numpy.arange(size)
        numpy.random.shuffle(arr)

    return arr   

matplotlib.pyplot.imshow(lena[numpy.ix_(xindices, yindices)])

import scipy.misc
import matplotlib.pyplot
import numpy.random
import numpy.testing

# 加载数组Lena
lena = scipy.misc.lena()
xmax = lena.shape[0]
ymax = lena.shape[1]

def shuffle_indices(size):
    arr = numpy.arange(size)
    numpy.random.shuffle(arr)

    return arr

xindices = shuffle_indices(xmax)
numpy.testing.assert_equal(len(xindices), xmax)
yindices = shuffle_indices(ymax)
numpy.testing.assert_equal(len(yindices), ymax)

# 绘制数组Lena
matplotlib.pyplot.imshow(lena[numpy.ix_(xindices, yindices)])
matplotlib.pyplot.show()