﻿ NumPy: Get the qr factorization of a given array - w3resource # NumPy: Get the qr factorization of a given array

## NumPy: Linear Algebra Exercise-17 with Solution

Write a NumPy program to get the qr factorization of a given array.

Sample Solution:

Python Code :

``````import numpy as np
a = np.array([[4, 12, -14], [12, 37, -53], [-14, -53, 98]], dtype=np.int32)
print("Original array:")
print(a)
q, r = np.linalg.qr(a)
print("qr factorization of the said array:")
print( "q=\n", q, "\nr=\n", r)
``````

Sample Output:

```Original array:
[[  4  12 -14]
[ 12  37 -53]
[-14 -53  98]]
qr factorization of the said array:
q=
[[-0.21199958 -0.27930103  0.93650794]
[-0.63599873 -0.68815735 -0.34920635]
[ 0.74199852 -0.66964945 -0.03174603]]
r=
[[ -18.86796226  -65.4018692   109.39178122]
[   0.            6.67798664  -25.24309237]
[   0.            0.            2.28571429]]
```

Python Code Editor:

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## Python: Tips of the Day

Negative Indexing:

In Python you can use negative indexing. While positive index starts with 0, negative index starts with -1.

```name="Welcome"
print(name)
print(name[-1])
print(name[0:3])
print(name[-1:-4:-1])

```

Output:

```W
e
Wel
emo```