Questions tagged [bagging]
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21 questions
1 vote
1 answer
77 views
Average training instances sampled with bagging
The book Hands-On Machine Learning has a section on Out-of-Bag Evaluation related to Decision Trees, where it's stated that, By default a BaggingClassifier samples m training instances with ...
0 votes
2 answers
743 views
How a Random forest "learns" or How loss (objective function value) is propagated back so that a random forest can "Improve"?
Every Blog and Youtube video talks about the same steps: Choose that you have to build N number of tree and do the task 2-5 ...
1 vote
1 answer
54 views
Can the product of tree regressions be represented by a single tree?
Assume that we have two separate tree regressions. I'm interested in understanding whether the product of tree regressions can be represented by a single tree. Would this be possible?
1 vote
1 answer
136 views
What are valid measures for reporting k-fold score in the case of confusion-matrix?
I know when model is made to predict a float value, a common approach to report the models validation is using k-fold technique and calculating the average of all folds accuracy (here is a similar ...
0 votes
1 answer
46 views
Where should I stop training if I want to bag models
Let's say I have a clear case of overfitting where my loss curves look like this (x axis are iterations): Now I would like to try bagging to reduce the variance, where should I stop models training? ...
2 votes
1 answer
436 views
Random LightGBM Forest
I'm not completly sure about the bias/variance of boosted decision trees (LightGBM especially), thus I wonder if we generally would expect a performance boost by creating an ensemble of multiple ...
2 votes
1 answer
1k views
Why can't we sample without replacement for each tree in a random forest if the subsample size is large enough?
Usually if we have $n$ observations, for each tree with form a bootstrapped subsample of size $n$ with replacement. On googling it one common explanation I've seen is that with replacement sampling is ...
5 votes
1 answer
755 views
Can Boosting and Bagging be applied to heterogeneous algorithms?
Stacking can be achieved with heterogeneous algorithms such as RF, SVM and KNN. However, can such heterogeneously be achieved in Bagging or Boosting? For example, in Boosting, instead of using RF in ...
0 votes
1 answer
2k views
Difference between bagging and pasting?
I found the definition: ...
1 vote
1 answer
209 views
Base model in ensemble learning
I've been doing some research on ensemble learning and read that for base models, model with high variance are often recommended (can't remember which book I read this from exactly). But, it seems ...
2 votes
1 answer
252 views
bagging vs. pasting in ensemble learning
I am bit confused about two concepts. From my understanding Bagging is when each data is replaced after each choice. so for example for each subset of data you pick one from population, replace it ...
0 votes
1 answer
63 views
Bagging Base models
If bagging reduces overfitting than the general statement that base learners of ensemble models should have high bias and low variance(that is should be undefiting) wrong?
1 vote
1 answer
509 views
Why the accuracy of my bagging model heavily affected by random state? [closed]
The accuracy of my bagging decision tree model reach up to 97% when I set the random seed=5 but the accuracy reduce to only 92% when I set random seed=0. Can someone explain why the huge gap and ...
2 votes
1 answer
1k views
Counting the number of trainable parameters in a gradient boosted tree
I recently ran the gradient boosted tree regressor using scikit-learn via: GradientBoostingRegressor() This model depends on the following hyperparameters: Estimators ($N_1$) Min Samples Leaf ($N_2$...
2 votes
1 answer
62 views
Can I do bagging method as improvement technique to decision tree in research?
Bagging use decision tree as base classifier. I want to use bagging with decision tree(c4.5) as base as the method that improve decision tree(c4.5) in my research that solve problem overfitting. Is ...