Timeline for why do we have to calculate the entropy of parent node in Information Gain?
Current License: CC BY-SA 4.0
4 events
| when toggle format | what | by | license | comment | |
|---|---|---|---|---|---|
| Nov 26, 2018 at 10:03 | vote | accept | Alireza HI | ||
| Nov 26, 2018 at 4:12 | comment | added | Sean Owen | Oh sure the parent entropy is constant when considering many splits. You are choosing the split with lowest child entropy regardless and that doesn't need parent entropy. However you may still need to compute information gain to, for example, see if the best split even achieves a positive gain at all. That does require knowing parent entropy. | |
| Nov 25, 2018 at 15:38 | comment | added | Alireza HI | well. I can compute children entropy with only the parent data. So we don't need parent entropy to compare children entropy. For example if parent entopry is 0.5 and children entropies are 0.3 and 0.4 I can just compare -0.3 and -0.4. Why do fomula calculate information gain using parent entropy. | |
| Nov 25, 2018 at 14:54 | history | answered | Sean Owen | CC BY-SA 4.0 |