Class Imbalance Measures

c1(X, y)

Calculates the Entropy of Class Proportions (C1) metric.

c2(X, y)

Calculates the Imbalance Ratio (C2) metric.
problexity.classification.c1(X, y)

Calculates the Entropy of Class Proportions (C1) metric.

\[C1=1+\frac{1}{log(n_c)}\sum^{n_c}_{i=1}p_{c_{i}}log(p_{c_{i}})\]
Parameters:

  • X (array-like, shape (n_samples, n_features)) – Dataset

  • y (array-like, shape (n_samples)) – Labels

Return type:

float

Returns:

C1 score

problexity.classification.c2(X, y)

Calculates the Imbalance Ratio (C2) metric.

\[C2=1-\frac{1}{IR}\]
Parameters:

  • X (array-like, shape (n_samples, n_features)) – Dataset

  • y (array-like, shape (n_samples)) – Labels

Return type:

float

Returns:

C2 score