FilesExpand file tree

 master

/

slicing.py

Copy path

Blame

More file actions

Blame

More file actions

Latest commit

 

History

History

History

executable file

·

123 lines (97 loc) · 2.02 KB

 master

/

slicing.py

Copy path

Top

File metadata and controls

• Code
• Blame

executable file

·

123 lines (97 loc) · 2.02 KB

Raw

Copy raw file

Download raw file

Open symbols panel

Edit and raw actions

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

20

21

22

23

24

25

26

27

28

29

30

31

32

33

34

35

36

37

38

39

40

41

42

43

44

45

46

47

48

49

50

51

52

53

54

55

56

57

58

59

60

61

62

63

64

65

66

67

68

69

70

71

72

73

74

75

76

77

78

79

80

81

82

83

84

85

86

87

88

89

90

91

92

93

94

95

96

97

98

99

100

101

102

103

104

105

106

107

108

109

110

111

112

113

114

115

116

117

118

119

120

121

122

import numpy as np

# Chapter 2 Beginning with NumPy fundamentals

#

# Demonstrates multi dimensional arrays slicing.

#

# Run from the commandline with

#

# python slicing.py

print("In: b = arange(24).reshape(2,3,4)")

b = np.arange(24).reshape(2,3,4)

print("In: b.shape")

print(b.shape)

#Out: (2, 3, 4)

print("In: b")

print(b)

#Out:

#array([[[ 0, 1, 2, 3],

# [ 4, 5, 6, 7],

# [ 8, 9, 10, 11]],

#

# [[12, 13, 14, 15],

# [16, 17, 18, 19],

# [20, 21, 22, 23]]])

print("In: b[0,0,0]")

print(b[0,0,0])

#Out: 0

print("In: b[:,0,0]")

print(b[:,0,0])

#Out: array([ 0, 12])

print("In: b[0]")

print(b[0])

#Out:

#array([[ 0, 1, 2, 3],

# [ 4, 5, 6, 7],

# [ 8, 9, 10, 11]])

print("In: b[0, :, :]")

print(b[0, :, :])

#Out:

#array([[ 0, 1, 2, 3],

# [ 4, 5, 6, 7],

# [ 8, 9, 10, 11]])

print("In: b[0, ...]")

print(b[0, ...])

#Out:

#array([[ 0, 1, 2, 3],

# [ 4, 5, 6, 7],

# [ 8, 9, 10, 11]])

print("In: b[0,1]")

print(b[0,1])

#Out: array([4, 5, 6, 7])

print("In: b[0,1,::2]")

print(b[0,1,::2])

#Out: array([4, 6])

print("In: b[...,1]")

print(b[...,1])

#Out:

#array([[ 1, 5, 9],

# [13, 17, 21]])

print("In: b[:,1]")

print(b[:,1])

#Out:

#array([[ 4, 5, 6, 7],

# [16, 17, 18, 19]])

print("In: b[0,:,1]")

print(b[0,:,1])

#Out: array([1, 5, 9])

print("In: b[0,:,-1]")

print(b[0,:,-1])

#Out: array([ 3, 7, 11])

print("In: b[0,::-1, -1]")

print(b[0,::-1, -1])

#Out: array([11, 7, 3])

print("In: b[0,::2,-1]")

print(b[0,::2,-1])

#Out: array([ 3, 11])

print("In: b[::-1]")

print(b[::-1])

#Out:

#array([[[12, 13, 14, 15],

# [16, 17, 18, 19],

# [20, 21, 22, 23]],

#

# [[ 0, 1, 2, 3],

# [ 4, 5, 6, 7],

# [ 8, 9, 10, 11]]])

print("In: s = slice(None, None, -1)")

s = slice(None, None, -1)

print("In: b[(s, s, s)]")

print(b[(s, s, s)])

#Out:

#array([[[23, 22, 21, 20],

# [19, 18, 17, 16],

# [15, 14, 13, 12]],

#

# [[11, 10, 9, 8],

# [ 7, 6, 5, 4],

# [ 3, 2, 1, 0]]])