is there a way to normalize [-3,1] to ${\begin{bmatrix} \dfrac{-3}{\sqrt{10}}\\ \dfrac{1}{\sqrt{10}}\\ \end{bmatrix}}$ with python?

Question

I am learning SVD by following this MIT course

The lecturer is trying to normalize a vector

$${\begin{bmatrix} -3\\ 1\\ \end{bmatrix}}$$

to

$${\begin{bmatrix} \dfrac{-3}{\sqrt{10}}\\ \dfrac{1}{\sqrt{10}}\\ \end{bmatrix}}$$

I tried this with Python NumPy

np.linalg.norm(v1,ord=2,axis=1,keepdims=True)

and got

array([[3.],
       [1.]])

I would like to get something like this

[[-0.9486833 ],
[ 0.31622777]]

is there a way with Python (for instance, NumPy) to do the job? any other 3rd party library is also appreciated.

Answer 1

You have already computed that, but you've not bound the output to a variable, also called name in python. Try the following snippet:

result = np.linalg.norm(v1,ord=2,axis=1,keepdims=True)
print(result)

---

Based on the edit, I update the answer. As you may find answers to your question, a typical way to find what you need is something like the following function:

def normalize(v):
    norm = np.linalg.norm(v)
    if norm == 0: 
       return v
    return v / norm

Equivalently, there is a function called normalize in sklearn.preprocessing which can be employed for your task.