where 𝑋 𝑖 and 𝑌 𝑖 are the 𝑖-th observations of the variable 𝑋 and 𝑌, 𝑋 ̅ is the average of variable 𝑋, 𝑅(𝑋 𝑖 ) is the ranking of the 𝑖-th observation of the variable 𝑋 and n is the number of observations. Binary classification performance was evaluated using the Matthews Correlation Coefficient (MCC, Eq. 3) at the threshold that maximizes its value.