# Tagged Questions

8 views

### Partially sparse vectors for training classifiers

Is it a bad idea to use a partially sparse vector for training a logistic regression classifier? By "partially sparse", I mean that about half the vector is actually dense, with real valued numbers ...
38 views

### Logistic Regression, SVM or NN?

Just attended Andrew Ng’s online course on ML and although I’ve understood the methods I seem to be missing the intuition on where to apply them in terms of classification problems. What are the ...
17 views

### Feature boosting via rescaling in logistic regression and linear SVMs

If I were expressing a problem in terms of binary features, all encoded as {0,1}, could I boost some features by encoding them as {0,2}? Would the effect change based on whether I used either of the ...
94 views

### Interpreting conflicting results from Random Forest & Logistic Regression?

I am using SKLearn and Statsmodel in python to build a RF and Logistic Regression, respectively. I have a feature that the RF indicates is important (feature importance of 0.202, closely behind #1 ...
25 views

### How to isolate impact of event in a product's lifecycle?

I'm trying to figure out how a single event affects sales numbers of a song. For example, see what the effect of being featured in iTunes store compared to songs with comparable previous download ...
24 views

### Does it work better to subtract mean of data in logistic regression?

I am using logistic regression to predict $X \rightarrow Y \in \{0, 1\}$ based on the featurization $\phi(X)$. The training objective function is \mathcal{L} = ...
29 views

### mixing binary and real-valued features with SGD

I'm going to be using a logistic regression model and using SGD to determine the feature weights. Is it OK for me to use a mix of binary and real features, without doing anything like scaling or ...
641 views

### What does the name “Logistic Regression” mean?

I am checking an implementation of Logistic Regression from here. After I reading that article, it seems the important part is the find the best coefficients to determine the sigmoid function. So I ...
24 views

### semisupervised classification training on all or part of unlabeled data

I have 3 sets of data. A positively labeled dataset. An unlabeled dataset that has for sure positive (around 75%) and negative data. An unlabeled dataset that has for sure positive data and maybe ...
31 views

### PCA + L1 equivalent to elastic net?

I am performing a logistic regression on a rather big dataset (700k+ samples and 1k+ features). I suspect that a lot of these features will be highly correlated and multicollinearity can be an issue. ...
31 views

### Softmax regression or $K$ binary logistic regression

For a multi-class classification problem, we can use $K$ binary logistic classifiers, or one softmax regression classifier, so how to make the choice between the two? IMHO, the $K$ binary logistic ...
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### Use a different loss function for cross validation in liblinear

I am trying to learn a L2 regularized Logistic regression model in liblinear. I need a way to specify the C parameter which I do by cross validation. However, the loss/accuracy measure in cross ...
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### Specifying the validation dataset for liblinear

I am trying to use the liblinear logistic regression model with L2 regularization. I don't want the training data to be splitted for the cross validation. I want to specify my own validation set for ...
30 views

### how to handle (many) false positives in training dataset for logistic regression classifier

I want to train a logistic regression dataset. I have a quite big training data set ( >100 000) and have around 10 features I can train on. Half of my training data is negative training data and I ...
86 views

### Example of how the log-sum-exp trick works in Naive Bayes

I have read about the log-sum-exp trick in many places (e.g. here, and here) but have never seen an example of how it is applied specifically to the Naive Bayes classifier (e.g. with discrete features ...
47 views

### Data preparation and machine algo for ad click prediction

I am an ml noob. I have a task at hand of predicting click probability given user information like city, state, os version, os family, device, browser family browser version, city, etc. I have been ...
47 views

### What is the difference between Binary Clasification and Multiclass classification?

Apology for posting almost one question daily. I am trying to learn some aspects of Statistical Machine learning, so every day many questions coming and if I am not finding answer in my offline peer ...
31 views

### Is there a stats tool for this analysis I run in excel?

I am trying to find a statistical or machine learning tool that replicates this analysis I am doing manually in excel. Each row in my data set is a user. ...
124 views

### Intuitive explanation of Bayesian logistic regression?

I'm looking for an intuitive explanation of Bayesian Logistic Regression (I'm using it for texts if that's relevant). It seems that this article presents it, but it's, uh, way too mathy. Thanks!
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### How can I apply LR with non-linear features?

My training data looks like this: ...
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### How can I improve the accuracy of my logistic regression code, which tests the accuracy using the 10-fold cross-validation technique?

How can I improve the accuracy of my logistic regression code, which tests the accuracy using the 10-fold cross-validation technique? I have implemented this code using ...
36 views

### Machine learning visualize dataset obtained from machine learning

I have analyzed text by finding sentiments of it. Basically have a huge file with text and its associated sentiment. Obtained by doing Machine learning. Used logistic regression algorithm. Now I want ...
19 views

### How can I use logistic regression with categorical variables? [duplicate]

I want to use logistic regression for binary classification on a dataset. I have 14 features in the dataset, and all but one are continuous. I have one categorical variable that represents a ...
131 views

### Question regarding parameters and variable selection in Mahout algorithm for logistic regression

Below is the list of parameters in Mahout logistic regression. What does "passes" mean? In detail please --passes passes the number of times to pass over the input data ...
44 views

### What is the posterior probability of the data given the model used for model averaging with Bayesian Logistic Regression?

I am trying to learn about Bayesian Model Averaging using Bayesian Logistic Regression (Genkin, A., Lewis, D. D., & Madigan, D. (2007). Large-scale Bayesian logistic regression for text ...
64 views

### Ensemble of models with different feature spaces

BACKGROUND I have data in which the dependent variable is binary with a highly-skewed distribution: <1% records are 1 (doers), >99% records are 0 (non-doers). I'm using logistic regression to ...
206 views

### How to calculate p values in logistic regression with gradient descent algorithm

In logistic regression, the gradient descent algorithm for calculating coefficients can be described this way: Until convergence, do  \beta := \beta + \alpha \frac{\partial L}{\partial \beta} ...
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### Beginner - How can I use ranked values in my Logistic Regression?

I am running a Logistic Regression on some data to predict if a webpage is "good" or "bad". I got the dataset from a finished Kaggle competiton here (train.tsv). I extract the second column of this ...
190 views

### Bootstrap aggregation (bagging) of logistic regression classifiers

So I'm taking N bootstrap samples and training N logistic regression classifiers on these samples. Each classifier gives me some probability of being in a binary class and then I average these N ...
52 views

### How to decide the number of Hidden layers and number of neurons in an Artificial neural network?

How to decide the number of Hidden layers and number of neurons in an Artificial neural network ? I am having an artificial neural network for a rainfall prediction application which is having four ...
152 views

### How to improve a Fraud Classification Model?

I built a classification model (Logistic Regression) in order to classify data in Fraud or Not Fraud. This data is related with online CNP (Card Not Present) transactions and after choosing some ...
421 views

### Logistic Regression\SVM implementation in Mahout

I am currently working on sentimental analysis of twitter data for one of telecom company data.I am loading the data into HDFS and using Mahout's Naive Bayes Classifier for predicting the sentiments ...
134 views

### Machine learning with trinomial features

I have 100,000 students who have each answered some multiple choice questions. Given their performance I want to work out what the chances are of a particular student answering the next question ...
261 views

### Machine Learning to Predict Class Probabilities

I am looking for classifiers that output probabilties that examples belong to one of two classes. I know of logistic regression and naive Bayes, but can you tell me of others that work in a similar ...
377 views

### Differences Between Logistic Regression in Statistics and in Machine Learning

I just found out that machine learning also has logistic regression as one of its methods. Can someone please tell me the differences between logistic regression in statistics and machine learning? ...
155 views

### Correlated features produce strange weights in Logistic Regression

I have a data set with highly positively correlated features that I'm classifying with LR. AFAIK correlated weights are not a problem in the same way they are in Naive Bayes - overcounting will not ...
608 views

### Intuition behind logistic regression

Recently I began studying machine learning, however I failed to grasp the intuition behind logistic regression. The following are the facts about logistic regression that I understand. As the ...
160 views

### Machine Learning System Design: a practical advice

Recently, I stared working on a machine learning competition hosted on Kagge.com. As the first step, a quick and dirty system was developed using Logistic Regression (LR). After running the system ...
327 views

### Why does my ROC curve look like this (is it correct?)

I have a ROC curve generated for a multivariate logistic regression. Does it look correct? This is what I've done: Solve $\theta_0 + \theta_1X_1 + \theta_2X_2 ... = Y$ for the $\theta$s Iterate ...
98 views

### Validating logistic regression - formulas needed for simulation

This is related to a data classification problem having a Boolean output variable. Summary: Once I perform the ML task using Logistic regression, I get the required coefficients. I use the ...
637 views

### How do you report percentage accuracy for glmnet logistic regression?

I am using glmnet where my dependent variable is binary (class 0, class 1). I want to report percentage accuracy of the model. So I use the ...
162 views

### Is there overfitting in my modelling approach despite cross-vaidation?

My model is predicting a binomial dependent variable with a rich feature space of 20,000 independent variables. I am using the penalized logistic regression from the glmnet package, which works for ...
104 views

### Sharing a model trained on confidential data

I have a regularized logistic regression model using scikit-learn and would like to share it with others, however the data it is trained on is confidential and must remain protected. The model uses ...
361 views

### Online logistic regression? [duplicate]

Here is my problem: I am developing an embedded system for some classification task. I am using Logistic Regression as my classifier. Now I train my classifier, and download my model on to my machine. ...
134 views

### Fitting a logistic regression using lassoglm in matlab [duplicate]

I am fitting a logistic regression model using lassoglm in matlab. I issued the following command ...
70 views

### How does Logistic regression classifier modelize the dataset?

I'm working on a system that be able to detect the hand contour. So I have 270 instance in my dataset: 7 class of hand contour, 8 feature vectors of each instance. Firstly, I used Weka to determine ...
483 views

### Logistic regression as classifier and overfitting

I am using logistic regression to classify data into two classes. The variable to predict (Y) is either 0 or 1. I have found a rather good estimation of Y by logistic regression, and ended up using ...
115 views

### Using priors to detect an effect? logistic Bayesian regression

I have designed an idea and am looking for similar approaches in other literature/areas or if I have applied the Bayesian concepts wrongly. Here is a statement of my problem: I am modeling the ...