Gini from AUC

Problem

Convert AUC to the Gini coefficient: Gini = 2 * AUC - 1.

Hint

The Gini coefficient rescales AUC so that random is 0 and perfect is 1.

case 1

in: [0.5]

expected: 0

case 2

in: [0.7]

expected: 0.3999999999999999

case 3

in: [1]

expected: 1

case 4

in: [0]

expected: -1

Starter codePython

def gini_from_auc(auc):
    # Your code here
    pass

4 test cases · run your code against them in the editor