python zeros用法實例

　　編程就是踩坑的過程。今天又踩了一個坑，做個積累吧。

在給數組賦初始值的時候，經常會用到0數組，而Python中，我們使用zero（）函數來實現。在默認的情況下，zeros創建的數組元素類型是浮點型的，如果要使用其他類型，可以設置dtype參數進行聲明。下面通過一個例子來說明：

　　１默認參數的例子：

　　

import numpy as np

r = 10
c = 10

D0 = np.zeros((11,11))
#D0 = np.zeros((11,11),dtype=int)

D0[0, 1:] = 32767
D0[1:, 0] = 32767

for i in range(r):
        for j in range(c):
            D0[i + 1, j + 1] = 1 
print D0
~                  

　　運行結果：

[[  0.00000000e+00   3.27670000e+04   3.27670000e+04   3.27670000e+04
    3.27670000e+04   3.27670000e+04   3.27670000e+04   3.27670000e+04
    3.27670000e+04   3.27670000e+04   3.27670000e+04]
 [  3.27670000e+04   1.00000000e+00   1.00000000e+00   1.00000000e+00
    1.00000000e+00   1.00000000e+00   1.00000000e+00   1.00000000e+00
    1.00000000e+00   1.00000000e+00   1.00000000e+00]
 [  3.27670000e+04   1.00000000e+00   1.00000000e+00   1.00000000e+00
    1.00000000e+00   1.00000000e+00   1.00000000e+00   1.00000000e+00
    1.00000000e+00   1.00000000e+00   1.00000000e+00]
 [  3.27670000e+04   1.00000000e+00   1.00000000e+00   1.00000000e+00
    1.00000000e+00   1.00000000e+00   1.00000000e+00   1.00000000e+00
    1.00000000e+00   1.00000000e+00   1.00000000e+00]
 [  3.27670000e+04   1.00000000e+00   1.00000000e+00   1.00000000e+00
    1.00000000e+00   1.00000000e+00   1.00000000e+00   1.00000000e+00
    1.00000000e+00   1.00000000e+00   1.00000000e+00]
 [  3.27670000e+04   1.00000000e+00   1.00000000e+00   1.00000000e+00
    1.00000000e+00   1.00000000e+00   1.00000000e+00   1.00000000e+00
    1.00000000e+00   1.00000000e+00   1.00000000e+00]
 [  3.27670000e+04   1.00000000e+00   1.00000000e+00   1.00000000e+00
    1.00000000e+00   1.00000000e+00   1.00000000e+00   1.00000000e+00
    1.00000000e+00   1.00000000e+00   1.00000000e+00]
 [  3.27670000e+04   1.00000000e+00   1.00000000e+00   1.00000000e+00
    1.00000000e+00   1.00000000e+00   1.00000000e+00   1.00000000e+00
    1.00000000e+00   1.00000000e+00   1.00000000e+00]
 [  3.27670000e+04   1.00000000e+00   1.00000000e+00   1.00000000e+00
    1.00000000e+00   1.00000000e+00   1.00000000e+00   1.00000000e+00
    1.00000000e+00   1.00000000e+00   1.00000000e+00]
 [  3.27670000e+04   1.00000000e+00   1.00000000e+00   1.00000000e+00
    1.00000000e+00   1.00000000e+00   1.00000000e+00   1.00000000e+00
    1.00000000e+00   1.00000000e+00   1.00000000e+00]
 [  3.27670000e+04   1.00000000e+00   1.00000000e+00   1.00000000e+00
    1.00000000e+00   1.00000000e+00   1.00000000e+00   1.00000000e+00
    1.00000000e+00   1.00000000e+00   1.00000000e+00]]

 

　　２　參數為整形的例子：

import numpy as np

r = 10
c = 10

#D0 = np.zeros((11,11))
D0 = np.zeros((11,11),dtype=int)

D0[0, 1:] = 32767
D0[1:, 0] = 32767

for i in range(r):
        for j in range(c):
            D0[i + 1, j + 1] = 1 
print D0

　　運行結果：

[[    0 32767 32767 32767 32767 32767 32767 32767 32767 32767 32767]
 [32767     1     1     1     1     1     1     1     1     1     1]
 [32767     1     1     1     1     1     1     1     1     1     1]
 [32767     1     1     1     1     1     1     1     1     1     1]
 [32767     1     1     1     1     1     1     1     1     1     1]
 [32767     1     1     1     1     1     1     1     1     1     1]
 [32767     1     1     1     1     1     1     1     1     1     1]
 [32767     1     1     1     1     1     1     1     1     1     1]
 [32767     1     1     1     1     1     1     1     1     1     1]
 [32767     1     1     1     1     1     1     1     1     1     1]
 [32767     1     1     1     1     1     1     1     1     1     1]]

　　可以看出，該zeros默認的是float類型，要使用別的類型需要加符號的，我就是在這個上面躺槍了。