vectorization is required in python when we are dealing with matrics. With the evolution of deep learning it has gained more lime-light.

Here is the execution time comparison of vectorised and non vectorised code.

# initialisation of array

```
import numpy as np
a=np.array([1,2,3,4])
print(a)
```

output-

`[1 2 3 4]`

# initialise numpy array

```
import time
A = np.random.rand(1000000)
B = np.random.rand(1000000)
```

```
# calculating execution time using vectorization
tic = time.time()
C =np.dot(A, B)
toc =time.time()
```

`print('total time taken in vectorised multiplication' + str(toc-tic) + 'mili-seconds')`

total time taken in vectorised multiplication 0.002000093460083008 mili-seconds

```
# calculating execution time using non vectorization codetic = time.time()
for i in range(1000000):
C = C +A[i]*B[i]
print(C)
toc= time.time()
print('total time taken in non-vectorised code'+ str(toc-tic) +' mili seconds')
```

749296.5132501889 total time taken in non-vectorised code0.6779999732971191 mili seconds.

## コメント