﻿ NumPy - Subtract the mean of each row from each array element

# Advanced NumPy Exercises - Subtract the mean of each row from each element of a 3x3 array

## NumPy: Advanced Exercise-4 with Solution

Write a NumPy program to create a 3x3 array with random values and subtract the mean of each row from each element.

Sample Solution:

Python Code:

``````import numpy as np
# create a 3x3 array with random values
arr = np.random.rand(3, 3)
print("Original array elements:")
print(arr)
# subtract the mean of each row from each element
row_means = np.mean(arr, axis=1, keepdims=True)
print("\nMean of each row:")
print(row_means)
arr_subtracted = arr - row_means
print("\nSubtract the mean of each row from each element:")
print(arr_subtracted)
``````

Sample Output:

```Original array elements:
[[0.61550214 0.59670368 0.5847669 ]
[0.73449098 0.79990957 0.42938855]
[0.811186   0.19465177 0.93097873]]

Mean of each row:
[[0.59899091]
[0.65459637]
[0.6456055 ]]

Subtract the mean of each row from each element:
[[ 0.01651124 -0.00228723 -0.01422401]
[ 0.07989461  0.14531321 -0.22520782]
[ 0.1655805  -0.45095373  0.28537323]]
```

Explanation:

In the above exercise -

arr = np.random.rand(3, 3): This line of code creates a 3x3 NumPy array arr with random values between 0 and 1 using the rand() function from the np.random module.

row_means = np.mean(arr, axis=1, keepdims=True): This line computes the mean of each row in arr using the mean() function from the NumPy module. The axis=1 argument specifies that we want to compute the means along the rows, and the keepdims=True argument ensures that the resulting array has the same shape as arr with a new axis for the means.

arr_subtracted = arr - row_means: This code subtracts the row means from each element in the corresponding row of arr to obtain a new array arr_subtracted.

Python-Numpy Code Editor:

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