'DataFrame' object has no attribute 'as_matrix'

The 'as_matrix' method has been deprecated in pandas since version 0.23.0 and removed in version 1.0.0. To convert a DataFrame to a NumPy array, you can use the 'values' attribute. For example:

import pandas as pd
import numpy as np

df = pd.DataFrame({'A': [1, 2, 3], 'B': [4, 5, 6]})
array = df.values
print(array)

This will output:

array([[1, 4],
       [2, 5],
       [3, 6]])

Note that the resulting array will have the same data type as the original DataFrame. If you need to convert the data type, you can use the 'astype' method.