Methods and principles of selecting a subset of attributes for use in further modelling

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How to explain difference of importance between feature selection and model quality?

I have a data collection with a mixed feature set consisting of both numerical features and text features. The number of numerical features is quite small, i.e., 6, comparing to the number of text ...
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1answer
74 views

Random forest importance differs between rf$importance and importance()

My model is working ok (the AUC is 0.7) but the importances from a randomForest run for my binary classification problem differ depending on how I retrieve them. Is ...
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35 views

Predictive features with high presence in one class

I am doing a logistic regression to predict the outcome of a binary variable, say whether a journal paper gets accepted or not. The independent variable or predictors are all the phrases used in these ...
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1answer
73 views

Numeric example of data for special case of stepwise linear regression

Stepwise Regression works as follows if I'm correct: fit the initial model add the variable which has its f-stat larger than a in-threshold and repeat step 2. if there are no candidates to enter - ...
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15 views

Why the maxStages argument in biglars.fit does not work

Why doesn't the biglars.fit function work when maxStages is specified? I've tried multiple values and multiple ways of casting $y$ but it doesn't work. ...
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3answers
388 views

How to divide feature set for selection and training

I have training data with 260 observations that have a total of 7 classes. Each observation has 120 features. I applied feature selection based on the Bhattacharyya Algorithm and got the top 40 ...
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1answer
51 views

finding an optimal subgroup of binary indicators

My dependent variable is continuous variable that measures the (potential) success of a person in some activity. I have hundreds of binary indicators, each indicates about the existence of a specific ...
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143 views

Cross validation for variable selection and coefficient shrinkage?

Is cross validation an appropriate technique for variable selection and regression coefficient shrinkage? A former colleague of mine used 10-fold CV to compare the regression coefficients from the ...
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159 views

Metric warning using caret's rfe

I am using the caret package to do feature selection with rfe while training a knn ...
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40 views

Variable selection (automated)

I was wondering whether the following mechanical selection procedure will result in a possible bias. First let me introduce the first procedure, we start with a model and only look at the t-value and ...
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32 views

Lasso-ing the order of a lag?

Suppose I have longitudinal data of the form $\mathbf Y = (Y_1, \ldots, Y_J) \sim \mathcal N(\mu, \Sigma)$ (I have multiple observations, this is just the form of a single one). I'm interested in ...
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11 views

Sparse variable selection algorithms that account for parameter changes

I am variable selecting for a time-series forecasting model that has parameters sampled from a high variance sampling distribution centred near zero and that undergo changes over time. Each predictor ...
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2answers
549 views

Why does the Lasso provide Variable Selection?

I've been reading Elements of Statistical Learning, and I would like to know why the Lasso provides variable selection and ridge regression doesn't. Both methods minimize the residual sum of squares ...
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154 views

When would I choose Lasso over Elastic Net

What are the scenarios where Lasso is likely to perform better than Elastic Net (out of sample prediction)?
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89 views

What if Lasso selects transformed terms but not untransformed terms

Suppose I have standard normal features $X_i \in \{X_i : i \in \{1,...,1000\}\}$. I extend this set of predictors with transformations as follows: $\{X_i,X_i^2,X_iI(X_i > 0) : i \in ...
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1answer
125 views

Best subset selection

My statistical learning text claims that for best subset selection, 2^p total models must be fit through regression if for p covariates, we fit p choose k models at each k, k = 1,...,p. I interpret ...
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29 views

Recursive Feature Elimination Fails to Output as Expected

Currently I am using rfe function in the "caret" package to do feature selection. There are 380 variables as input candidates. I have done many trials and I noticed that something weird always ...
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113 views

Find weight of features for feature selection

I have a data set of videos from which I need to recognize the emotion of the speaker. For that reason I have some markers on the face of the speaker. I detect their movement as the speaker speaks and ...
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2answers
172 views

Variable selection with groups of predictors that are highly correlated

What variable selection approach should I consider if I have thousands of predictors with clusters that are extremely correlated? For example I might have a predictor set $X:= ...
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1answer
74 views

Extract important features

Here is my situation: - A huge amount of data - 600 features - Only one class is provided Now, my question is how can I reduce the number of features to important ones? In another word, all of these ...
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1answer
206 views

Decision trees variable (feature) scaling and variable (feature) normalization (tuning) required in which implementations?

In many machine learning algorithms, feature scaling (aka variable scaling, normalization) is a common prepocessing step Wikipedia - Feature Scaling -- this question was close Question#41704 - How and ...
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31 views

Confusion related to feature engineering

I was reading this tutorial where they mentioned ...
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4answers
127 views

Machine learning input relationships

After learning about a few machine-learning models (NN, SVM, decision trees), I was wondering if these models are able to find inherent relationships when learning. For example, if I feed it two ...
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1answer
110 views

How Can I use some variables selected by LASSO?

I am very new about statistics. So, please understand if my question is somewhat awkward, and please give me related any advice. I have some data set. X = 500 x 100 (500 observations x 100 ...
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2answers
179 views

Variable selection in time-series forecasting

I have a time-series forecasting task and would like some input on variable selection and regularisation. My problem has the following characteristics: 2,000,000 sample size. Most of the time, no ...
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3answers
727 views

Selecting the best subset of variables for parsimonious binary logistic regression models

In addition to PROC VARCLUS, randomForest, glmnet, and assessing multicollinearity among potential predictor variables (without regards to the outcome of interest), I am seeking other methods of ...
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43 views

Network/structure learning

Given a data set $\mathbf{X}\in\mathbb{R}^{n\times p}$, where $n$ is the number of samples (observations) and $p$ is the number of features, I would like to know what kind of methods exist for ...
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1answer
67 views

Distinguishing two datasets

I have two datasets from some Web store (like Amazon). Datasets have one and the same structure. Each record in these datasets has the following attributes: ...
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1answer
35 views

Interpretation of feature selection task

So I am given the following question Data set sample5.txt has a 20-dimensional input $x$ in $\mathbb{R}^{20}$ but we suspect that many of these are actually irrelevant. Could you model the ...
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1answer
86 views

k-fold feature selection

I have a data set with 20 K variables. I have tried to select some features via Boruta and FSelector but I could not achieve ...
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27 views

Connection between feature selection and hypothesis testing

I have a dataset for cell-phone accounts and I am trying to predict whether or not an account will cancel given some input features. One such feature is the number of devices an account owns. I am ...
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88 views

Variable reduction by means of ANOVA?

I have a typical problem with several variables and a large amount of data which are not important right now. The goal of the study is to relate variable $Y$ with variables $X_1,X_2,...,X_n$. I have ...
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64 views

LASSO method: prediction for multi-dimentional reponses

I have a feature matrix, that is 'X' 2000 (observation) x 200 (variable). I also have a response matrix, that is 'Y' 2000 (response) x 2 (variable). I would like to apply LASSO method to the data ...
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112 views

Time series classification

I am classifying a set of time series inputs after creating independent features from every $n$ samples and running machine learning algorithms. I get good accuracy based on many error metrics on the ...
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69 views

Confusion related to feature selection

Well my objective is to predict solar energy radiation at a particular location given some features like wind, temperature, humidity ... I have a total data for 10 years where I have the measurement ...
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1answer
185 views

Implement Forward, Backward, Step and LASSO in VB .NET

My client wants me to implement Variable selection methods i.e. Forward, Backward, Step and LASSO in VB .Net platform including p-value and AIC. I have no idea about the steps involved to calculate ...
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1answer
47 views

How to deal with features only available for a few instances?

I am working with a regression problem. I have some features which are only available for a few instances. But with those few instances based on those features we can build a model which gives ...
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2answers
689 views

Random Forest: IncNodePurity and Feature Selection for Binary Logistic Regression

After creating a Random Forest object using randomForest with around 500 candidate variables, I used importance(object) to ...
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1answer
174 views

Combining Exploratory Factor Analysis with Random Forest for Binary Logistic Regression Feature Selection

For those of you familiar with Exploratory Factor Analysis (EFA) and Random Forest (RF), I have recently had an idea of combining these two methods to reduce the number of potential predictor ...
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2answers
2k views

Feature selection with Random Forests

I have a dataset with mostly financial variables (120 features, 4k examples) which are mostly highly correlated and very noisy (technical indicators, for example) so I would like to select about max ...
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1answer
241 views

Exploratory Factor Analysis for Binary Logistic Regression Variable Selection

I have a great interest in learning new methods(at least to me) of variable selection in regards to binary logistic regression when I am working with over 500 potential predictor variables and have ...
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145 views

Weak Classifiers weights/contribution in Adaboost and Real adaboost?

In Adaboost according to SAMME implementation, the $\alpha$ determines the contribution of the weak classifier. Here is the Adaboost algorithm $\alpha$ is in step 2. (c) Now in RealAda boost I ...
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72 views

Feature selection using correlation

I am trying to do some feature selection using correlation. However, I found that my features are not that correlated. The highest correlation was 0.08. So I am not sure if this is a useful thing to ...
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128 views

Features selection by filter methods for multivariate time series

I have a data set in which the samples are multivariate (about 30 variable/features) time series. These samples refer to two classes. I would like to select the variables more relevant to discriminate ...
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1answer
238 views

Using Mutual Information for Binary Logistic Regression Variable Selection

In addition to proc varclus, randomForest, and assessing multicollinearity among potential predictor variables, I am seeking ...
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1answer
64 views

Can I select a subset of predictor variables without using step()?

I have a set of 20 predictor variables, and I want to formulate a regression model by applying my own variable selection technique basically with backward approach (just for an experiment purpose.) ...
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0answers
62 views

Out-of-bag estimate biased by correlated features

I have a data set with a small number of samples (322) and a large number of features (318.976). My data consists of images, and I want to train a binary classifier. Since I have such a small amount ...
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0answers
29 views

Correct order of performing imputation and variable selection

This is a general question about performing data analysis. I have a data set with ~1000 sample size and 200 features. Some of features have more than 50% missing or even higher. The missing pattern is ...
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1answer
145 views

A Bayesian perspective on omitted-variable bias (and other covariate-selection bias problems)

As I know OVB, from a frequentist education, when you leave a variable $(z)$ out of your control set $(X)$ that is correlated with both your independent variable of interest (treatment $T$) and your ...
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243 views

Feature importance scores of SVM multiclass one-vs-one design

Info about dataset: 5 classes, 200 trials, 100 features. (I know about the trial to feature ratio being very low, but can not avoid this here and still got well enough classification results.) ...