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How to Adjust LightGBM Parameters Like `min_child_samples` When Increasing Training Data?

I'm training a LightGBM model and currently facing a dilemma regarding parameter tuning when increasing the amount of training data. Initially, I split my dataset into 90% for training and 10% for ...
aLIEz's user avatar
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1 answer
34 views

What is the effect on a LightGBM ranker model of having many groups where all observations have the same target value?

I'm working on a recommender system where users are recomended 5 items at a time. We build a dataset by saving the 5 items along with feature values and a "relevant" target value (1 if the ...
gasbag_1's user avatar
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75 views

In my case XGBoost is faster than LightGBM. How do I achieve better speed?

I hope that this place is the right one to ask the following question: I'm training a machine learning model. The train size is 85000x55. 49x ...
jigga's user avatar
  • 101
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0 answers
27 views

LightGBM binary classifier: how can I know which values of categorical feature offer the most discrimination?

I am familiar with using methods such as lgb.plot_split_value_histogram to investigate the most used splitting points along numerical features. Is there an ...
Learning is a mess's user avatar
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1 answer
60 views

SHAP values are explaining the wrong output value

I was checking the local accuracy property of the SHAP values. It states that for a data point $(X,y)$, the SHAP values $(s_1,s_2,s_3,...)$ of features $(x_1,x_2,x_3,...)$ sum up to the difference of ...
Abhay Gupta's user avatar
2 votes
0 answers
90 views

Tuning the learning rate parameter for GBDT models

I've always been taught that decreasing the learning rate parameter in gbdt models such as XGBoost, LightGBM and Catboost will improve the out-of-sample performance, assuming the number of iterations ...
Casper's user avatar
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0 answers
34 views

Gradient boosting algorithm implemented in LightGBM

I'm currently reading the documentation of LightGBM and I'm wondering which gradient boosting algorithm is exactly implemented there if choose boosting parameter as "gbdt" or "dart?&...
Julian's user avatar
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1 vote
0 answers
52 views

How do I know the appropriate number of iterations when using Miceforest for imputation?

I want to know how to avoid overfitting without having to increase the number of iterations excessively in Python with the Miceforest library. I know you can make a correlation map of data sets but I ...
Eduardo Dimas's user avatar
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0 answers
38 views

LightGBM Regressor miscalibratred/underestimating on high fitted values and overestimating on low fitted values

I'm training a pretty standard LightGBM regressor and noticing a strange pattern with the residuals (see images below--I'm bunching the predicted values and taking the observed average for the group). ...
dfried's user avatar
  • 101
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0 answers
82 views

R [Warning] No further splits with positive gain, best gain: -inf in lightgbm training

I read through some answers, it seems many people face this message before. The answer seems there is no further need to split the tree, so you need to adjust the super parameter to make new splitting....
cloudscomputes's user avatar
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1 answer
74 views

In lightgbm,what is a uniform drop?

I read through document of lightgbm,it just tells this parameter, but didn't give much explanation for it. The explanation: ...
cloudscomputes's user avatar
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0 answers
268 views

Missing values handling in LightGBM

I'm a bit confused about the handling of missing data by LightGBM. I'm using the R package but my question should not be language-specific. In a regression setting with no categorical feature, I have ...
Augustin's user avatar
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0 answers
12 views

Histogram creation in lightgbm in the train API and the scikit-learn API. Is it always benefitial to use the train API?

In the LightGBM for python we have a scikit-learn API in which (either for regression or for classification) there is fit method whose documentation is fit(X, y, sample_weight=None, init_score=None, ...
figs_and_nuts's user avatar
0 votes
1 answer
349 views

How to assign sample weight for regression problem

I'm trying to model a forecasting problem where I'm trying to forecast for the following month. I am using LightGBM Regressor class for it and it giving me a decent ...
Krishnang K Dalal's user avatar
1 vote
0 answers
111 views

Understanding lgbm histogram building

...
figs_and_nuts's user avatar
0 votes
1 answer
236 views

Is there a way to focus mainly on high precision when fitting a tree model?

I have a dataset with 95% false and 5% true labels, some 200000 samples overall, I'm fitting a LightGBM model. I mainly need to focus on high precision and have low number of false positives, I don't ...
Fireant's user avatar
0 votes
1 answer
388 views

randomness in lightgbm model training

What are the parameters that add randomness to the training of a lightgbm model? (for a large dataset) I have tried setting all parameters as default and letting bin_construct_sample_cnt be greater ...
kimo's user avatar
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0 answers
1k views

lightgbm issue ValueError: Input numpy.ndarray or list must be 2 dimensional

Problem Build prediction accuracy model using lightgbm on New York Taxi Duration dataset. Problem is "ValueError: Input numpy.ndarray or list must be 2 dimensional" with lightgbm.predict() ...
Data Science Analytics Manager's user avatar
1 vote
1 answer
464 views

Why is monotonic constraint disabled when using MAE as an objective to LGBM?

I tried to use monotonic constraints in LGBM, but if I use mean absolute error as an objective, it gives a warning that monotonic constraints cannot be done in l1. What is the reason? Thanks!
morqueatsz's user avatar
0 votes
1 answer
81 views

Combining results from classifiers trained on different test/train splits results in higher accuracy

I have developed a classifier model using LightGBM. The accuracy of the model varies significantly because of the test_train_split state(between 83% and 91%). This ...
Nemo_the_scientist's user avatar
0 votes
1 answer
116 views

Why the order of the fearures affects synapse LightGBM predictions?

I am using LighGBM Classifier and Regressor and it seems that the order of the features I am adding, affect the predictions of the model. Everytime I change the order, another result comes up and with ...
Chrysa Rinou's user avatar
4 votes
1 answer
745 views

Optuna Median Pruner n_warmup_steps

For Gradient Boosting Models such as XGBOOST and LGBM does n_warmup_steps in optuna.pruners.MedianPruner refer to the minimum number of folds evaluated before pruning is triggered? I.e. if number of ...
Kjetil Haukås's user avatar
1 vote
1 answer
774 views

Grid-search for a multi-output regression task using Scikit-learn's API

I'm trying to make a model for a multi-output regression task where $y=(y_1, y_2,..., y_n)$ is a vector rather than a single scalar. I am using Scikit-learn's ...
Hassan Abedi's user avatar
0 votes
0 answers
53 views

Multiclass classification (gradient boosted trees) predictions distribution using softmax()

Let's consider a multiclass problem where the target is composed by 20% class 'A', 50% of class 'B' and 30% of class 'C'. The model is trained and then the class predictions are obtained via the ...
simon's user avatar
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0 votes
1 answer
265 views

Impact of many zeros in LightGBM Regressor training set [duplicate]

I have a LightGBM Regressor model with 15 features. 5 of these features have 98.7% NA for the training set. All five of the features are NA for each row. I impute the missing values with zero before I ...
ashton's user avatar
  • 1
1 vote
0 answers
241 views

Sklearn Lightgbm 3.3.2 API

I have a model object from a model and am trying to pass in the dataframe for scoring, it is kicking me an error: ...
Tinkinc's user avatar
  • 111
2 votes
1 answer
988 views

Online Learning/Continual Learning for tree-based Algorithms

Every example I come across any kind of iterative learning on Random Forest/XGBoost/LightGBM, it just continuously grows the number of estimators for new batches of data by ...
OliverHennhoefer's user avatar
1 vote
2 answers
1k views

How to improve Regression RMSE with LightGBM

I have the following dataset: https://raw.githubusercontent.com/Joffreybvn/real-estate-data-analysis/master/data/clean/belgium_real_estate.csv I want to predict the price column, based on the other ...
Luis Valencia's user avatar
1 vote
0 answers
130 views

How to use GBDT with EFB or GOSS with EFB in LightGBM? or is it implemented by default?

The paper for Lightgbm talks about goss and efb, I want to know how to use these together. I know of the hyper-parameter 'boosting' can be used to set boosting as gbdt, or goss, or dart. But how to ...
SS16's user avatar
  • 75
1 vote
1 answer
830 views

How can I implement lambda-mart with lightgbm?

I have a learning to rank task at hand and I want to use the lightgbm implementation of LambdaMART. I'm also following this notebook. ...
Akash Dubey's user avatar
1 vote
0 answers
556 views

How does exactly eval_set and RandomizedSearchCV work for LightGBM?

How does RandomizedSearchCV form the validation sets, while I also defined an evaluation set for LGBM? Is it formed from the train set I gave or how does the evaluation set comes into the validation? ...
morqueatsz's user avatar
0 votes
0 answers
54 views

Constructing pandas DF with model trained categorical variable

I've trained a lightGBM model on a dataset X where X has a categorical (in the pandas sense) variable. This model trains fine and when I predict using it all looks good - I can even change the value ...
Saleem Akhtar's user avatar
0 votes
1 answer
263 views

SOS: Working LightGBM model script to find best model

I have been trying to get a working LightGBM model which I can train on my data, select the best performing model with highest f1 score and then use it obtain the f1 score on the testing data. However,...
am98's user avatar
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-1 votes
0 answers
51 views

Does lightGBM handle multicollinearity? [duplicate]

I have a dataset after feature selection of around 6500 features and 10,000 data rows. I am using LightGBM model. I want to know if I should check the feature set for multicollinearity. If two or more ...
SS16's user avatar
  • 75
1 vote
1 answer
246 views

Model Performance on external validation Set really low?

I am using the LGBM model for binary classification. My train and test accuracies are 87% & 82% respectively with cross-validation of 89%. ROC-AUC score of 81%. But when evaluating model ...
SS16's user avatar
  • 75
0 votes
3 answers
1k views

Is my model overfitting ? Training Acc :93 % test accuracy 82%

I am using LGBM model for binary classification. After hyper-parameter tuning I get Training accuracy 0.9340 Test accuracy 0.8213 can I say my model is overfitting?...
SS16's user avatar
  • 75
0 votes
0 answers
300 views

LightGBM predict_proba in thousandths place

Can someone explain to me how my lightgbm classification model's predict_proba() is in thousandths place for the positive class: ...
Tinkinc's user avatar
  • 111
2 votes
1 answer
304 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 ...
CutePoison's user avatar
1 vote
1 answer
113 views

Proof of GOSS algorithm in lightGBM paper

In the LightGBM paper the authors make use of a newly developed sampling method GOSS to reduce the number of data instances needed for finding the best split of a ...
HannesZ's user avatar
  • 121
0 votes
1 answer
235 views

Incorporating data over time into lightgbm

So I'm in the situation where I know what it is I'm trying to find, but not the terminology for it and I think that's why a lot of my google searches are directing me in the wrong direction, so ...
user1777900's user avatar
1 vote
1 answer
4k views

LightGBM eval_set - what to do when I fit the final model (there's no test data left)

I'm using LightGBM's eval_set feature when fitting my model. This enables early stopping on the number of estimators used. ...
Lewis Morris's user avatar
1 vote
1 answer
263 views

Understanding feature_parallel distributed learning algorithm in LightGBMClassifier

I want to understand feature_parallel algorithm in LightGBMClassifier. It describes how it is done traditionally and how LightGBM...
figs_and_nuts's user avatar
3 votes
3 answers
190 views

Example for Boosting

Can someone exactly tell me how does boosting as implemented by LightGBM or XGBoost work in real case scenerio. Like I know it splits tree leaf wise instead of level wise, which will contribute to ...
Chris_007's user avatar
  • 193
1 vote
0 answers
46 views

Fractional Differencing/Differentiation for Non-Time based Model; Look-ahead bias?

I have time-series data, but instead of using a time-based model like RNN, I've decided to approach my classification problem using an lgbm classifier. To do so, I have modified the data, such that ...
Michael Mech's user avatar
2 votes
2 answers
733 views

Optimizing MAE degrades MAE metrics

I have run a lighgbm regression model by optimizing on RMSE and measuring the performance on RMSE: ...
Mark531's user avatar
  • 121
0 votes
1 answer
3k views

LightGBM regressor score function?

I'm trying to find what is the score function for the LightGBM regressor. In their documentation page I could not find any information regarding the function used to calculate the score attribute...
An old man in the sea.'s user avatar
0 votes
2 answers
156 views

Churn prediction model doesn't predict good on real data

I am working currently on churn prediction problem. As an input I use data from date warehouse for a period 082016 - 032021(one row per month for each customer). Based on this data I have created a ...
zdz's user avatar
  • 113
0 votes
1 answer
23 views

Additional business rules in ensemble methods (RF, Boosted Trees)

How is it possible (if at all) to implement additional business constraints to an ensemble machine learning model, such as random forests or boosted trees? These additional business rules can be ...
Jivan's user avatar
  • 165
2 votes
0 answers
2k views

Binary classification with imbalanced dataset, about lightgbm output probability distribution

I trained a binary classifier for an imbalanced dataset. I did two experiments: lightgbm classifier, boosting_type='gbdt', objective='cross_entropy', SMOTE upsample After training the lgbm model, I ...
JisongXie's user avatar
2 votes
2 answers
273 views

confused on "real score" vs "decision value" in classification trees

I'm reading the guide to XGBoost and am confused about the distinction it draws between the scoring systems of decision trees and classification/regression trees. The paragraph I am hung up on is: A ...
Sinnombre's user avatar
  • 153