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 of binary classification task ([0,1])

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 of binary classification task ([0,1])

Return type:

float

Returns:

C2 score