Ensemble Learning
What's so special about CatBoost?
CatBoost is based on gradient boosting. A new machine learning technique developed by Yandex that outperforms many existing boosting algorithms like XGBoost, Light GBM. While deep learning algorithms requires lots of data and computational power, boosting algorithms are still in need for most of the business problems. However boosting algorithms like XGBoost takes hours to train and sometimes you'll get frustrated while tuning hyper-parameters. On the other hand, CatBoost is easy to implement and very powerful.
r/MachineLearning - [D] Tips on improving random forest predictive accuracy when # of features is really low?
Normally when I do RF projects I use some sort of feature selection method to choose which features to use. Then I fit the RF model onto those features. Then to test accuracy / related metrics I use cross validation, confusion matrices, etc. However in this case I only have two given features. I don't want to just literally run a RF model on those two features as my whole entire project. I'm thinking gradient boosting is what I should learn?
Diabetes Prediction with Ensemble Techniques
Here, for this data we will build models to predict the "Outcome" i.e. Diabetes Yes or No and we will perform Ensemble techniques to better our predictions. We will be using several techniques to do that, each technique is briefed as we keep building our codes below. Here is the link to this data from where it can be downloaded.
Customer Churn Prediction Using Machine Learning: Main Approaches and Models
Customer retention is one of the primary growth pillars for products with a subscription-based business model. Competition is tough in the SaaS market where customers are free to choose from plenty of providers even within one product category. Several bad experiences โ or even one โ and a customer may quit. And if droves of unsatisfied customers churn at a clip, both material losses and damage to reputation would be enormous. For this article, we reached out to experts from HubSpot and ScienceSoft to discuss how SaaS companies handle the problem of customer churn with predictive modeling. You will discover approaches and best practices for solving this problem. We'll discuss collecting data about client relationship with a brand, characteristics of customer behavior that correlate the most with churn and explore the logic behind selecting the best-performing machine learning models. Customer churn (or customer attrition) is a tendency of customers to abandon a brand and stop being a paying client of a particular business. The percentage of customers that discontinue using a company's products or services during a particular time period is called a customer churn (attrition) rate. One of the ways to calculate a churn rate is to divide the number of customers lost during a given time interval by the number of acquired customers, and then multiply that number by 100 percent.
How to Choose among Three Forecasting Models: Machine Learning, Statistical and Expert - Bain & Company
Forecasting methods usually fall into three categories: statistical models, machine learning models and expert forecasts, with the first two being automated and the latter being manual. Statistical methods, including time series models and regression analysis, are considered traditional, while machine learning methods, such as neural network, random forest and the gradient-boosting model, are more modern. Yet when selecting a forecasting method, the "modern vs. traditional" or "automated vs. manual" comparisons can mislead. Preferences will depend on the modeler's training: Those with data science training will prefer machine learning models, while modelers with business backgrounds have more trust in expert forecasts. In fact, each of the three methods has different strengths and can play important roles in forecasting.
Generalized Integrated Gradients: A practical method for explaining diverse ensembles
Merrill, John, Ward, Geoff, Kamkar, Sean, Budzik, Jay, Merrill, Douglas
We introduce Generalized Integrated Gradients (GIG), a formal extension of the Integrated Gradients (IG) (Sundararajan et al., 2017) method for attributing credit to the input variables of a predictive model. GIG improves IG by explaining a broader variety of functions that arise from practical applications of ML in domains like financial services. GIG is constructed to overcome limitations of Shapley (1953) and Aumann-Shapley (1974), and has desirable properties when compared to other approaches. We prove GIG is the only correct method, under a small set of reasonable axioms, for providing explanations for mixed-type models or games. We describe the implementation, and present results of experiments on several datasets and systems of models.
Guided Random Forest and its application to data approximation
Gupta, Prashant, Jindal, Aashi, Jayadeva, null, Sengupta, Debarka
We present a new way of constructing an ensemble classifier, named the Guided Random Forest (GRAF) in the sequel. GRAF extends the idea of building oblique decision trees with localized partitioning to obtain a global partitioning. We show that global partitioning bridges the gap between decision trees and boosting algorithms. We empirically demonstrate that global partitioning reduces the generalization error bound. Results on 115 benchmark datasets show that GRAF yields comparable or better results on a majority of datasets. We also present a new way of approximating the datasets in the framework of random forests.
Explaining Predictions: Random Forest Post-hoc Analysis (randomForestExplainer package)
We can further evaluate the variable interactions by plotting the probability of a prediction against the variables making up the interaction. The interaction of these two variables are the most frequent interaction as seen in plot_min_depth_interactions. We plot the forest prediction against interactive variables with plot_predict_interaction. However, there is an error when the input supplied is a model created with parsnip. There is no error when the model is created directly from the randomForest package.
How We Teach Machines to Learn: Tree Boosting and Adversarial Networks - PROPRIUS
No matter how you prefer to learn, you have probably heard someone mention something about your particular "learning style." This seemingly simple phrase implies that there are many different ways to learn, and people can be better or worse at certain learning methods depending on personal preferences and circumstances. As it is with people, so we tend to make it for computers. Machine learning is moving forward at a fast rate thanks to researchers and programmers figuring out how to optimize the ways through which machines learn new information. Two methods in particular, called tree boosting and adversarial networks, work in tandem to produce encouraging results.
Using Machine Learning to Battle Antibiotic Resistance
The team applied a machine learning algorithm called extreme gradient boosting (XGBoost). Using those 10-mer counts, the computer designs decision trees to predict the right MICs. Each decision point uses one of the 10-mers to help it classify a given genome as resistant or susceptible to various drugs. The algorithm then assigns different levels of importance to each 10-mer, and designs trees repeatedly, in rounds called "boosts," until it gets the lowest error it can for its MIC predictions compared to the true MICs. The researchers ran the algorithm 10 times, each time leaving out a different tenth of their dataset.