TABLE 2.
Performance indices of different machine learning algorithms (MLP, GRNN, and ANFIS) for modeling and predicting shoot length, root length, number of nodes, number of shoots, and canopy surface area of Cannabis.
| Model | Performance index | Shoot length |
Shoot number |
Node number |
Root length |
Canopy surface area |
|||||
| Training | Testing | Training | Testing | Training | Testing | Training | Testing | Training | Testing | ||
| MLP | R2 | 0.972 | 0.954 | 0.625 | 0.421 | 0.717 | 0.390 | 0.938 | 0.900 | 0.953 | 0.928 |
| RMSE | 4.929 | 6.927 | 0.396 | 0.632 | 0.702 | 1.202 | 15.112 | 15.956 | 277.487 | 340.538 | |
| MBE | –0.090 | 1.673 | 0.009 | –0.001 | 0.017 | 0.260 | 0.001 | 2.259 | 30.952 | 25.016 | |
| GRNN | R2 | 0.983 | 0.964 | 0.733 | 0.714 | 0.791 | 0.744 | 0.941 | 0.914 | 0.962 | 0.944 |
| RMSE | 3.879 | 6.081 | 0.347 | 0.606 | 0.594 | 0.933 | 14.754 | 14.972 | 248.737 | 300.911 | |
| MBE | 0.001 | 1.540 | 0.001 | 0.012 | –0.001 | 0.063 | 0.001 | 2.581 | 0.001 | 2.388 | |
| ANFIS | R2 | 0.770 | 0.590 | 0.647 | 0.501 | 0.767 | 0.549 | 0.781 | 0.589 | 0.733 | 0.644 |
| RMSE | 17.538 | 23.327 | 0.407 | 0.557 | 0.650 | 0.942 | 41.881 | 39.007 | 1282.011 | 1282.697 | |
| MBE | –4.549 | –5.508 | 0.006 | –0.065 | –0.003 | 0.037 | 5.962 | 8.546 | –26.525 | –32.037 | |
ANFIS, adaptive neuro-fuzzy inference system; GRNN, generalized regression neural network; MBE, mean bias error; MLP, multilayer perceptron; R2, coefficient of determination; RMSE, root mean square error.