Random forest is a machine-learning classifier based on choosing random subsets of variables for each tree and using the most frequent tree output as the overall classification.

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Size of terminal node in decision tree/random forest?

I am having issues trying to understand what does the size of a terminal node in a decision tree means? Could anyone give me an easy explanation? I know a terminal node is a leaf node, the one that ...
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Creating a test set with imbalanced data

I am working on a binary random forest using R. mu data set consists of 300 cases classes 1 and 2100 cases class 0. I am planning to evaluate my model using the model prediction and the AUC and for ...
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Random Forest and missing values in numeric features

I'd like to use a random forest for predicting how long a person will stay a customer of our company. One feature I'd like to use is the average age of the customer's kids. The problem is some ...
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Random forest: Possibility to derive the characteristics of the predicted value?

Decision Trees stratify the feature space into different regions and fit the model in each region. With this method it's not difficult to derive the caracteristics of each individual taking the ...
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41 views

How do I implement missing value patterns?

I have a training data set and I was able to find some interesting patterns in the missing values, and I used binary variables in order to represent the missingness. I am going to train a model, say a ...
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33 views

Random Forest, dependent measurements

I have a following quiz: A random forest is used for classifying the disease state of patients based on measuring multiple genes. The dataset consists of 100 genes and 50 patients. However, ...
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24 views

In a random forest, is larger %IncMSE better or worse?

Once I have built a (regression) random forest model in R, the call rf$importance provides me with two measures for each predictor variable, ...
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59 views

Random Forest - Numeric and Dummy Variables together

I am trying to create a logistic regression model and a random forest model on the same data to predict probability of default. For the logistic regression model, I have created some dummy variables ...
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75 views

What measure of training error to report for Random Forests?

I'm currently fitting random forests for a classification problem using the randomForest package in R, and am unsure about how to report training error for these ...
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114 views

Does modeling with Random Forests require cross-validation?

As far as I've seen, opinions tend to differ about this. Best practice would certainly dictate using cross-validation (especially if comparing RFs with other algorithms on the same dataset). On the ...
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68 views

I built a random forest model in r…now what? [closed]

I've built a random forest model in R. All looks great in terms of my accuracy and AUC on the test set. How can I take extract the model so I can apply it to data in my database? For linear ...
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129 views

Huge Discrepancy between OOB and Cross Validation Random Forest

I am dealing with Random Forests at the moment. I observe huge discrepancies between OOB generalisation error estimation and cross validation. Originally, I used the scikit-learn package. But to ...
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20 views

What are the goodness of fit variables in classification trees?

I have used multivariate linear regression for one of my projects, and used r-square and p vals to evaluate the model. I couldn't find what such metric we would use for decision trees and random ...
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41 views

How does feature selection work in Random Forest?

I've been trying to improve the performance of my random forest model, and read the following paper on feature selection using random forest (see algorithm in section IV: Overfitting - A. Feature ...
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47 views

Interpreting % Var explained in Random Forest output

I've run a Random Forest in R using randomForest package. The fitted forest I've called: fit.rf. All I want to know is: When I type 'fit.rf' the output shows '% var explained' Is the % Var ...
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11 views

Random Forest Instance Proximities Training to Test

Using randomForest, I want to create a low-level projection of the instance proximities, as produced by MDSPlot(). However, I ...
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10 views

Sparse Categorical predictors with Categorical Response

I have a huge set of sparse Categorical predictors (500+) and a binary response variable, Dataset is mostly sparse. I tried using Random Forrest with very little success. Any suggestions?
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95 views

Classification with randomForest in R - always predicts 0

I have a data frame of approximately 11500 records. Each row of the frame has a response variable, isfastes, and a number of other predictors (size, cores, ...
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28 views

Is random forest a right approach?

I am pretty new to stat and having read some articles about applying random forest algorithm. I have a employee survey return which contains approx 200 questions say 50 questions per a theme so there ...
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31 views

Regression Tree Predictions

For various regression tree algorithms (e.g. GBM, Random Forest, Extra Trees), is there any sensible way to get predictions for new data when the independent variables for the new cases are much ...
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15 views

Fine Tune Model with Caret Package

I am using CARET package to fine tune random forest mtry parameter. In the package, tunelength parameter can be used to automate search for best mtry parameter. But the problem is the "tunelength" ...
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24 views

Classification Model on Single Feature?

this is my first time using StackExchange so forgive me if I commit any faux paus with this question, and it has only been a few months since I first started learning machine learning. In my ...
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44 views

Why is random forest inconsistent in text mining?

Earlier I've used SVM (rbf kernel) in text mining with success, and after that for similar text mining work with long texts I've used random forest with success as well. However in a recent kaggle ...
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45 views

A question about Dynamic Random Forest

On this article, Simon Bernard proposes a new approach for constructing Random Forest called Dynamic Random Forest. I am new on this subject, so after reading the article, I have a doubt regarding the ...
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47 views

How to interpret caret's variable importance and feature selection plots?

I am having some problems understanding the variable importance and feature selection graphs from ...
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36 views

Gini Algorithm for beginners

"Gini Algorithm" when is it used ? I mean what is it used for ? is it used for classification or building the tree ? or something else ? what are the alternative algorithms for the "Gini algorithm" ...
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55 views

How can 1 more feature disrupt a Random Forest's confusion matrix?

I'm trying to predict a binary variable with both random forests and logistic regression. I've got unbalanced classes (approx 1.5% of Y=1), so i'm calling ...
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55 views

Changing the sequence of variables in a random forest model changes the classification accuracy

I find that the classification accuracy of the random forest model changes when the sequence of the input variables change. E.g. ...
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43 views

Variable importance in party vs randomForest

I am getting completely different results from cforest and randomForest with regards to variable importance (mean decrease in accuracy): ...
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Can random forest be applied to predict an event rate for a time interval, for the following problem statement?

I have to predict which of the agents (in a direct selling business) could become sales leaders. This prediction has to be done just before every sales cycle (there are 2 week cycles across the year, ...
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Scikit Random forest pred_proba gives rounded off values

I am using random forest in scikit learn for classification and for getting the class probabilities , I used pred_proba function. But strangely it outputs probabilities rounded to first decimal place ...
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Reduce the FP rate for a Random Forest (sklearn)

I am working with the scikit-learn random forest classifier and I want to reduce the FP rate by increasing the number of trees needed for a successful vote from greater than 50% to say 75%, after ...
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45 views

Model to predict Residuals of another model

I am using a random forest for a 2 class classification problem. But eventually using probability of class "1" returned by the model for my task and not the label. I get AUC of about 70% Then I ...
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65 views

What functions do decision trees and random forests learn?

We know that training a function $y = f_\theta(x)$ (parameterised by $\theta$ in some fashion, for e.g., the class of linear functions) using data $\{(x_i, y_i)\}$ drawn i.i.d from some unknown ...
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Why is Logistic Regression called a Machine Learning algorithm?

If I understood correctly, in a Machine Learning algorithm, the model has to learn from its experience, i.e when the model gives the wrong prediction for the new cases, it must adapt to the new ...
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82 views

What does “node size” refer to in the Random Forest?

I do not understand exactly what is meant by node size. I know what a decision node is, but not what node size is.
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39 views

Can I Interpret the impact of variables like positive or negative on the model by Random Forest, as I can do by Logistic Regression

I have created a model for prediction of candidates presence or not . I have used Logistic Regression and Random Forest . By Logistic Regression, I got coefficients associated with 100 features and I ...
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22 views

random forest analysis with random(clustering) varible

My data consists of presence/absence (PA) of a trait in 354 plants collected from 127 collection sites as response, and a set of 25 climatic continuous variables in each site as predictors. The ...
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110 views

R package for Weighted Random Forest? classwt option?

I'm trying to use Random Forest to predict the outcome of an extremely imbalanced data set (the 1's rate is about only 1% or even less). Because the traditinal randomForest minimize the overall error ...
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68 views

Including Interaction Terms in Random Forest

Suppose we have a response Y and predictors X1,....,Xn. If we were to try to fit Y via a linear model of X1,....,Xn, and it just so happened that the true relationship between Y and X1,...,Xn wasn't ...
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57 views

Random Forest: Predictors have more than 53 categories? [duplicate]

What is the solution when we want to apply the Random Forest function in R to a predictor with more than 53 categories? ...
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26 views

Why the result of Random Forest Algorithm change a lot when all the parameters are kept the same?

I want to do some classification of some dataset with random forest. When I run the same script twice, two totally different(almost 5%) result were given by the program. I want to know whether random ...
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How does weka combine the decision trees in a random forest?

When building the random forest, I am wondering if Weka combine the decision trees by averaging their probabilistic prediction or if Weka let each decision tree vote for a unique class? Thank you in ...
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54 views

Random forest for panel data

I have a dataset with observations from about 50 countries and 20 years. My dependent variable is binary and I was wondering if I could use random forest to do out-of-sample predictions. My problem ...
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66 views

How do I set probability thresholds for a logistic regression and cutoffs in randomForest model to get a good confusion matrix?

Whenever I run a logistic regression, I need to set the threshold so that it groups probabilities higher than the threshold to my positive group: ...
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37 views

Resources for machine learning for time-dependent data

For the past year, I have spent the majority of my free time learning a variety of ML techniques (boosting, random forests, neural nets, SVMs etc.), but I have not been able to find a lot of material ...
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61 views

Random Forest: Different performance between training set and test set?

I'm a newbie learning Random Forest. When I use this method to predict my outcome and check with the same data set (training set), I see that the model fits almost perfectly the data. But when I ...
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42 views

Balancing random forest via cross validation. Difference between sample weight and cutoffs?

My random forest model of a simple binary target (0, 1) and is producing unbalanced results. i.e many more false positives than there are false negatives. In addition, '1' is a low percentage class, ...
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29 views

Random Forest in Pose Estimation

I am having problem in understanding the number of feature input to the Random forest mentioned in the paper below. Shotton, Jamie, et al. "Efficient human pose estimation from single depth images." ...
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27 views

Loss function for Random forest

I am working on a random forest model in R and want to use a different loss function from the default. Does random forest implementation in R allow for arbitrary loss functions?