Python编程深度学习计算库之numpy

liumiaocn:tmp liumiao$ pip install numpy
Collecting numpy
 Downloading https://files.pythonhosted.org/packages/b6/5e/4b2c794fb57a42e285d6e0fae0e9163773c5a6a6a7e1794967fc5d2168f2/numpy-1.14.5-cp27-cp27m-macosx_10_6_intel.macosx_10_9_intel.macosx_10_9_x86_64.macosx_10_10_intel.macosx_10_10_x86_64.whl (4.7MB)
  100% |████████████████████████████████| 4.7MB 284kB/s 
Installing collected packages: numpy
Successfully installed numpy-1.14.5
liumiaocn:tmp liumiao$

liumiaocn:tmp liumiao$ pip show numpy
Name: numpy
Version: 1.14.5
Summary: NumPy: array processing for numbers, strings, records, and objects.
Home-page: http://www.numpy.org
Author: Travis E. Oliphant et al.
Author-email: None
License: BSD
Location: /usr/local/lib/python2.7/site-packages
Requires: 
Required-by: 
liumiaocn:tmp liumiao$

liumiaocn:tmp liumiao$ cat np-1.py 
#!/usr/local/bin/python
import numpy as np
arr = [1,2,3,4]
print("array arr: ", arr)
np_arr = np.array(arr)
print("numpy array: ", np_arr)
print("doulbe calc : ", 2 * np_arr)
print("ndim: ", np_arr.ndim)
liumiaocn:tmp liumiao$ python np-1.py 
('array arr: ', [1, 2, 3, 4])
('numpy array: ', array([1, 2, 3, 4]))
('doulbe calc : ', array([2, 4, 6, 8]))
('ndim: ', 1)
liumiaocn:tmp liumiao$

liumiaocn:tmp liumiao$ cat np-2.py 
#!/usr/local/bin/python
import numpy as np
arithmetic = np.arange(0,16,2)
print(arithmetic)
print("ndim: ",arithmetic.ndim," shape:", arithmetic.shape)
#resize to 2*4 2-dim array
arithmetic.resize(2,4)
print(arithmetic)
print("ndim: ",arithmetic.ndim," shape:", arithmetic.shape)
#resize to 2*2*2 3-dim array
array = arithmetic.resize(2,2,2)
print(arithmetic)
print("ndim: ",arithmetic.ndim," shape:", arithmetic.shape)
liumiaocn:tmp liumiao$ python np-2.py 
[ 0 2 4 6 8 10 12 14]
('ndim: ', 1, ' shape:', (8,))
[[ 0 2 4 6]
 [ 8 10 12 14]]
('ndim: ', 2, ' shape:', (2, 4))
[[[ 0 2]
 [ 4 6]]
 [[ 8 10]
 [12 14]]]
('ndim: ', 3, ' shape:', (2, 2, 2))
liumiaocn:tmp liumiao$ 

liumiaocn:tmp liumiao$ cat np-3.py 
#!/usr/local/bin/python
import numpy as np
print("np.linspace(1,4,4):", np.linspace(1,4,4))
print("np.logspace(1,4,4):", np.logspace(1,4,4))
print("np.logspace(1,4,4,base=2):",np.logspace(1,4,4,base=2))
liumiaocn:tmp liumiao$ python np-3.py 
('np.linspace(1,4,4):', array([1., 2., 3., 4.]))
('np.logspace(1,4,4):', array([  10.,  100., 1000., 10000.]))
('np.logspace(1,4,4,base=2):', array([ 2., 4., 8., 16.]))
liumiaocn:tmp liumiao$

liumiaocn:tmp liumiao$ cat np-4.py 
#!/usr/local/bin/python
import numpy as np
print("np.zeros(6):",np.zeros(6))
print("np.zeros((2,3)):",np.zeros((2,3)))
print("np.ones(6):",np.ones(6))
print("np.ones((2,3)):",np.ones((2,3)))
print("np.random.random(6):",np.random.random(6))
print("np.random.random(6):",np.random.random(6))
print("np.random.random((2,3)):",np.random.random((2,3)))
print("np.random.seed(1234)")
np.random.seed(1234)
print("np.random.random(6):",np.random.random(6))
print("np.random.seed(1234)")
np.random.seed(1234)
print("np.random.random(6):",np.random.random(6))
liumiaocn:tmp liumiao$ python np-4.py 
('np.zeros(6):', array([0., 0., 0., 0., 0., 0.]))
('np.zeros((2,3)):', array([[0., 0., 0.],
    [0., 0., 0.]]))
('np.ones(6):', array([1., 1., 1., 1., 1., 1.]))
('np.ones((2,3)):', array([[1., 1., 1.],
    [1., 1., 1.]]))
('np.random.random(6):', array([0.06909968, 0.27468844, 0.59127996, 0.56973602, 0.45985047,
    0.95384945]))
('np.random.random(6):', array([0.62996648, 0.2824114 , 0.2698051 , 0.09262053, 0.50862503,
    0.96600255]))
('np.random.random((2,3)):', array([[0.66880129, 0.8834006 , 0.49458989],
    [0.28335563, 0.65711274, 0.76726504]]))
np.random.seed(1234)
('np.random.random(6):', array([0.19151945, 0.62210877, 0.43772774, 0.78535858, 0.77997581,
    0.27259261]))
np.random.seed(1234)
('np.random.random(6):', array([0.19151945, 0.62210877, 0.43772774, 0.78535858, 0.77997581,
    0.27259261]))
liumiaocn:tmp liumiao$