﻿ python – 将numpy数组拆分成块 - 代码日志

#### python – 将numpy数组拆分成块

``````blocks_that_have_stuff = []
my_array = getArray()
my_array.cut_into_blocks((10, 10))
for block_no, block in enumerate(my_array):
if numpy.count_nonzero(block) > 5:
blocks_that_have_stuff.append(block_no)
``````

``````import matplotlib.pyplot as plt
import numpy as np

def cut_array2d(array, shape):
arr_shape = np.shape(array)
xcut = np.linspace(0,arr_shape[0],shape[0]+1).astype(np.int)
ycut = np.linspace(0,arr_shape[1],shape[1]+1).astype(np.int)
blocks = [];    xextent = [];    yextent = []
for i in range(shape[0]):
for j in range(shape[1]):
blocks.append(array[xcut[i]:xcut[i+1],ycut[j]:ycut[j+1]])
xextent.append([xcut[i],xcut[i+1]])
yextent.append([ycut[j],ycut[j+1]])
return xextent,yextent,blocks

nx = 900; ny = 650
X, Y = np.meshgrid(np.linspace(-5,5,nx), np.linspace(-5,5,ny))
arr = X**2+Y**2

x,y,blocks = cut_array2d(arr,(10,10))

n = 0

for x,y,block in zip(x,y,blocks):
n += 1
plt.imshow(block,extent=[y[0],y[1],x[0],x[1]],
interpolation='nearest',origin='lower',
vmin = arr.min(), vmax=arr.max(),
cmap=plt.cm.Blues_r)
plt.text(0.5*(y[0]+y[1]),0.5*(x[0]+x[1]),str(n),
horizontalalignment='center',
verticalalignment='center')

plt.xlim([0,900])
plt.ylim([0,650])
plt.savefig("blocks.png",dpi=72)
plt.show()
``````