chapter 24

Numpy Practice Quesions Set-2

Example

Python

import numpy as np
a = np.arange(1,37).reshape(6,6)
a

Output

PowerShell

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],
       [25, 26, 27, 28, 29, 30],
       [31, 32, 33, 34, 35, 36]])

Example

Python

print(f"a[2][3] ==> {a[2][3]}")
print(f"a[2,3] ==> {a[2,3]}")

Output

PowerShell

a[2][3] ==> 16
a[2,3] ==> 16

Example

Python

oned_array = a[0,1:5]
twod_array = a[0:1,1:5]
print(f"using with indexing : {oned_array}")
print(f"using with slicing : {twod_array}")

Output

PowerShell

using with indexing : [2 3 4 5]
using with slicing : [[2 3 4 5]]

Example

Python

oned_array = a[0,1:5]
twod_array = a[0:1,1:5]
print(f"using with indexing : {oned_array}")
print(f"using with slicing : {twod_array}")

Output

PowerShell

using with indexing : [2 3 4 5]
using with slicing : [[2 3 4 5]]
array([[ 1,  2,  3,  4,  5,  6],
       [31, 32, 33, 34, 35, 36]])

Example

Python

a[::5,:]

Output

PowerShell

array([[ 1,  2,  3,  4,  5,  6],
       [31, 32, 33, 34, 35, 36]])
array([[ 9, 10],
       [15, 16],
       [21, 22]])

Example

Python

a[1:4,2:4]

Output

PowerShell

array([[ 9, 10],
       [15, 16],
       [21, 22]])

Example

Python

a[a%2==0]

Output

PowerShell

array([ 2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, 26, 28, 30, 32, 34, 36])

Example

Python

a[a%5==0]

Output

PowerShell

array([ 5, 10, 15, 20, 25, 30, 35])

Example

Python

# a[[row_indices],[column_indices]]
a[[1,2,4,5],[1,4,1,4]]

Output

PowerShell

array([ 8, 17, 26, 35])

Example

Python

# np.amin(a)
# np.min(a)
# a.min()
print(f"np.amin(a) ==> {np.amin(a)}")
print(f"np.min(a) ==> {np.min(a)}")
print(f"a.min() ==> {a.min()}")

Output

PowerShell

np.amin(a) ==> 1
np.min(a) ==> 1
a.min() ==> 1

Example

Python

# np.amax(a)
# np.max(a)
# a.max()
print(f"np.amax(a) ==> {np.amax(a)}")
print(f"np.max(a) ==> {np.max(a)}")
print(f"a.max() ==> {a.max()}")

Output

PowerShell

np.amax(a) ==> 36
np.max(a) ==> 36
a.max() ==> 36

Example

Python

print(f"np.sum(a) ==> {np.sum(a)}")
print(f"a.sum() ==> {a.sum()}")

Output

PowerShell

np.sum(a) ==> 666
a.sum() ==> 666

Example

Python

print(f"np.sum(a,axis=0) ==> {np.sum(a,axis=0)}")
print(f"a.sum(axis=0) ==> {a.sum(axis=0)}")

Output

PowerShell

np.sum(a,axis=0) ==> [ 96 102 108 114 120 126]
a.sum(axis=0) ==> [ 96 102 108 114 120 126]

Example

Python

print(f"np.mean(a) ==> {np.mean(a)}")
print(f"a.mean() ==> {a.mean()}")

Output

PowerShell

np.mean(a) ==> 18.5
a.mean() ==> 18.5

Example

Python

print(f"np.median(a) ==> {np.median(a)}")

Output

PowerShell

np.median(a) ==> 18.5

Example

Python

print(f"np.var(a) ==> {np.var(a)}")
print(f"a.var() ==> {a.var()}")

Output

PowerShell

np.var(a) ==> 107.91666666666667
a.var() ==> 107.91666666666667

Example

Python

print(f"np.std(a) ==> {np.std(a)}")
print(f"a.std() ==> {a.std()}")

Output

PowerShell

np.std(a) ==> 10.388294694831615
a.std() ==> 10.388294694831615