Finding the nearest value from a given value in an array is a common task in data analysis and scientific computing. NumPy is a popular Python library for numerical computing that provides efficient and powerful functions for manipulating arrays. NumPy provides several methods to find the nearest value in an array, which are mentioned below:
1. Using "np.argpartition()":
- The code creates a NumPy array
arrand variable with value
6, this value is not in the array but we will find the one closest to it.
- It then calculates the absolute difference between each element of the array and the given value using
np.abs(arr - value).
np.argpartition()function is used to get the index of the element with the smallest absolute difference. The
1in the function call specifies that we only need the index of the first smallest element.
- Finally, the index is used to retrieve the nearest value from the array, which is printed using
2. Using "np.searchsorted()":
- The initialization of variables
valueis done in the same way as in the method above.
searchsorted()method of the NumPy array is used to find the index where
valuewould be inserted into
arrto maintain sorted order. This method returns the index of the first element in
arrthat is greater than
- A boolean conditional expression is used to get the nearest value to where,
→ if the index is greater than 0 (meaning that
valueis not less than the first element of
→ either the index is equal to the length of
valueis greater than or equal to the last element of
→ the absolute difference between
valueand the element at the index before the found index is less than the absolute difference between
valueand the element at the found index, then the value at the index before the found index is assigned to
nearest. Otherwise, the value at the found index is assigned to
With these functions, it is easy to find the nearest value from a given value in a NumPy array efficiently and accurately.