Shannon Entropy
MediumMachine LearningMathArray
Description
Given an array labels of class labels, return the Shannon entropy -sum(p_i·log2(p_i)) where p_i is the proportion of each class, rounded to 4 decimal places.
Examples
Input:
labels = [0,0,1,1]Output:
1Explanation:
Summing the negative proportion-weighted log2 proportions gives an entropy of 1.
Input:
labels = [1,1,1]Output:
0Explanation:
Summing the negative proportion-weighted log2 proportions gives an entropy of 0.
Input:
labels = [0,1,2,3]Output:
2Explanation:
Summing the negative proportion-weighted log2 proportions gives an entropy of 2.
Constraints
- •
1 ≤ labels.length ≤ 10⁴