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Finding the closest value in a NumPy array
Programming
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schedule Mar 9, 2022
Last updated Python●NumPy
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expand_more To find the closest value in the Numpy array to a certain value, we use the following function:
def find_closest(arr, val): idx = np.abs(arr - val).argmin() return arr[idx]
We use this like follows:
arr = np.array([1,4,10])find_closest(arr, 6)
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Explanation
The basic idea is that, the smaller the difference between the number in the array and your value, the closer they are:
np.array([1,4,10]) - 6
array([-5, -2, 4])
Since we do not care whether the number in the array is larger or smaller than our value, we take the absolute value:
np.abs(np.array([1,4,10]) - 6)
array([5, 2, 4])
Next, we want to extract the index of the smallest number in this array since it represents the number that is closest to our value:
idx = np.abs(arr - val).argmin()idx
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Finally, we obtain the actual value that corresponds to this index:
return arr[idx]
Published by Isshin Inada
Edited by 0 others
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