Method | No selection | Channel groups | Feature groups | ||
---|---|---|---|---|---|
 |  | Forward | Backward | Forward | Backward |
RF number of features | 41 × 21=861 | 2 × 21=42 | 12 × 21=420 | 41 × 3=123 | 41 × 17=697 |
RF error rate | 0.019 | 0.034 | 0.011 | 0.058 | 0.016 |
SVM number of features | 41 × 21=861 | 2 × 21=42 | 12 × 21=420 | 41 × 3=123 | 41 × 8=328 |
SVM error rate | 0.011 | 0.030 | 0.017 | 0.045 | 0.015 |