﻿ NumPy - Sum each row of a 4x4 array with random values

# Advanced NumPy Exercises - Find the sum of a 4x4 array containing random values

## NumPy: Advanced Exercise-3 with Solution

Write a NumPy program to create a 4x4 array with random values and find the sum of each row.

Sample Solution:

Python Code:

``````import numpy as np
# create a 4x4 array with random values
arr = np.random.rand(4, 4)
# find the sum of each row
row_sum = np.sum(arr, axis=1)
print("Original array:")
print(arr)
print("\nSum of each row:")
print(row_sum)
``````

Sample Output:

```Original array:
[[0.97150665 0.4384906  0.52444497 0.45505872]
[0.98733409 0.3498058  0.44414235 0.08707591]
[0.86342298 0.68227614 0.02548033 0.83086213]
[0.7784747  0.3086618  0.49636261 0.70016215]]

Sum of each row:
[2.38950093 1.86835815 2.40204158 2.28366126]
```

Explanation:

In the above exercise -

arr = np.random.rand(4, 4): This line creates a 4x4 NumPy array arr with random values between 0 and 1 using the rand method from numpy.random module.

row_sum = np.sum(arr, axis=1): This line calculates the sum of each row in the arr numpy array using the sum method from NumPy. The axis parameter is set to 1, which means that the sum is calculated across each row. The resulting array row_sum is a 1-dimensional array with 4 elements, where each element corresponds to the sum of a row in the original arr array.

Python-Numpy Code Editor:

Have another way to solve this solution? Contribute your code (and comments) through Disqus.

What is the difficulty level of this exercise?

Test your Programming skills with w3resource's quiz.

﻿

## Python: Tips of the Day

Decapitalizes the first letter of a string:

Example:

```def tips_decapitalize(s, upper_rest=False):
return s[:1].lower() + (s[1:].upper() if upper_rest else s[1:])
print(tips_decapitalize('PythonTips'))
print(tips_decapitalize('PythonTips', True))
```

Output:

```pythonTips
pYTHONTIPS
```

We are closing our Disqus commenting system for some maintenanace issues. You may write to us at reach[at]yahoo[dot]com or visit us at Facebook