Table 2. Algorithm tuning parameters.
Algorithm | Tuning parameter |
---|---|
Logistic regression | - |
Random forest | mtry = 12 |
Support Vector Machine | C = 8; sigma = 4.69·10−11 |
Naïve Bayes | fL = 0; adjust = 1 |
K-nearest neighbor | K = 5 |
Artificial Neural Network | Size = 11; decay = 0.1 |
GLMNET | Alpha = 0.8; lambda = 0.21 |
Algorithm tuning parameters selected by repeated (5 times) 10-fold cross-validation in a grid. Mtry: Number of variables for splitting at each tree node in a random forest; C: regularization parameter that controls the trade off between the achieving a low training error and a low testing error; sigma: determines how fast the similarity metric goes to zero as they are further apart; fL: Laplace smoother; adjust: adjust the bandwidth of the kernel density; K = number of nearest neighbours; size: number of units in hidden layer; decay: regularization parameter to avoid over-fitting; alpha: regularization parameter; lambda: penalty on the coefficients