Study Group: 巾凡哥出品 品質保證 python 12 (numpy)
Tags: jupyter-notebook, numpy, python, 讀書會
a = np.array([1, 2, 3, 4, 5])
"""
array([1, 2, 3, 4, 5, 6])
"""
np.zeros(10)
"""
array([0., 0., 0., 0., 0., 0., 0., 0., 0., 0.])
"""
a = np.ones(10)
"""
array([1., 1., 1., 1., 1., 1., 1., 1., 1., 1.])
"""
np.empty(5)
"""
array([ 1. , 2.75, 6. , 10.75, 17. ])
"""
np.arange(5)
np.arange(2, 9, 2)
"""
array([2, 4, 6, 8])
"""
np.linspace(1, 100, num=10)
"""
array([ 1., 12., 23., 34., 45., 56., 67., 78., 89., 100.])
"""
np.ones(10, dtype=np.float64)
"""
array([1., 1., 1., 1., 1., 1., 1., 1., 1., 1.])
"""
v = np.array([2, 1, 5, 3, 7, 4, 6, 8])
np.sort(v)
"""
array([1, 2, 3, 4, 5, 6, 7, 8])
"""
a = np.array([1, 2, 3, 4])
b = np.array([5, 6, 7, 8])
np.concatenate((a,b))
"""
array([1, 2, 3, 4, 5, 6, 7, 8])
"""
np.array([[0,1,2,3],[4,5,6,7]])
"""
array([[0, 1, 2, 3],
[4, 5, 6, 7]])
"""
array_example = np.array([ [ [0, 1, 2, 3],
[4, 5, 6, 7]],
[[0, 1, 2, 3],
[4, 5, 6, 7]],
[[0 ,1 ,2, 3],
[4, 5, 6, 7]]])
array_example.ndim # dimension
"""
3
"""
array_example.size
"""
24
"""
array_example.shape
"""
(3, 2, 4)
"""
a =np.arange(12)
a
"""
array([ 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11])
"""
a < 4
"""
array([ True, True, True, True, False, False, False, False, False,
False, False, False])
"""
a[a==4]
"""
array([4])
"""
a = np.array([[1 , 2, 3, 4], [5, 6, 7, 8], [9, 10, 11, 12]])
a
"""
array([[ 1, 2, 3, 4],
[ 5, 6, 7, 8],
[ 9, 10, 11, 12]])
"""
a[ (a > 5) & (a<10) ]
"""
array([6, 7, 8, 9])
"""
a
"""
array([[ 1, 2, 3, 4],
[ 5, 6, 7, 8],
[ 9, 10, 11, 12]])
"""
np.nonzero( (a > 5) & (a<10))
"""
(array([1, 1, 1, 2]), array([1, 2, 3, 0]))
"""
a1 = np.array([[1, 1],
[2, 2]])
a2 = np.array([[3, 3],
[4, 4]])
a1
"""
array([[1, 1],
[2, 2]])
"""
a2
"""
array([[3, 3],
[4, 4]])
"""
np.vstack((a1, a2))
"""
array([[1, 1],
[2, 2],
[3, 3],
[4, 4]])
"""
np.concatenate((a1, a2))
"""
array([[1, 1],
[2, 2],
[3, 3],
[4, 4]])
"""
np.hstack((a1, a2))
"""
array([[1, 1, 3, 3],
[2, 2, 4, 4]])
"""
x = np.arange(1, 25).reshape(4, 6)
x
"""
array([[ 1, 2, 3, 4, 5, 6],
[ 7, 8, 9, 10, 11, 12],
[13, 14, 15, 16, 17, 18],
[19, 20, 21, 22, 23, 24]])
"""
np.vsplit(x, 4)
"""
np.vsplit(x, 4)
np.vsplit(x, 4)
[array([[1, 2, 3, 4, 5, 6]]),
array([[ 7, 8, 9, 10, 11, 12]]),
array([[13, 14, 15, 16, 17, 18]]),
array([[19, 20, 21, 22, 23, 24]])]
"""
np.hsplit(x, 3)
"""
[array([[ 1, 2],
[ 7, 8],
[13, 14],
[19, 20]]),
array([[ 3, 4],
[ 9, 10],
[15, 16],
[21, 22]]),
array([[ 5, 6],
[11, 12],
[17, 18],
[23, 24]])]
"""
a = np.arange(5)
b = np.arange(1,6)
a
"""
array([0, 1, 2, 3, 4])
"""
b
"""
array([1, 2, 3, 4, 5])
"""
a / 5
"""
array([0. , 0.2, 0.4, 0.6, 0.8])
"""
a.max()
# 4
a.min()
# 0
a.sum()
# 10