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Questions tagged [feature-selection]

In machine learning, this is the process of selecting a subset of most relevant features to construction your data model.

Feature selection is an important step to remove irrelevant or redundant features from our data. For more details, see Wikipedia.

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A Feature Selection Algorithm POE1ACC for features with continuous value

i want to implement the algorithm of "Probability of Error and Average Correlation Coefficient". (more info Page 143. It is a algorithm to elect unused features from set of features. As far as i know, this algorithm is not limited to boolean valued…
Asqan
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SVM How to calculate tf-df of test documents in document classification?

In my SVM, i am using tf-idf on the documents for feature extraction. These tf-idf are calculated on the whole of training documents. Now when i get a test-document that i want to classify, how do i generate the vector for it ? I used stemming…
Ashish Negi
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Features in Document clustering/classification?

This may sound very naive but i just wanted to be sure that when talking in Machine Learning terminology, features in Document Clustering is words which are chosen from a document, if some are discarded after stemming or as stop-words. I am trying…
Ashish Negi
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Active frame extraction from motion capture

I am new to this area - I have a background in a Gait and Posture. I have a series of motion files of timestamped coordinates (containing X, Y, and Z in mm) with a number of joints (30). What would be the simplest way to extract the following from…
Daniel
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How often and where is each feature used in the Viola-Jones detector?

This is a question about the Viola-Jones Algorithm (used for face detection) as described here http://en.wikipedia.org/wiki/Viola%E2%80%93Jones_object_detection_framework and in the original…
Kenyakorn Ketsombut
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OpenCV: How to compare the performances of feature detectors and extractors using images of a real scene by different point of view?

I'm trying to build a loop closure algorithm, but before to start the development I would like to test which feature descriptor work better on a real dataset. I have a pair of images of a corridor taken in both direction, one entering in a room and…
Michele mpp Marostica
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Supervised Learning

The question is about combining output probabilities from detectors. Each of my detector d_i gives me a probability p_i of object presence in the scene. I have a labelled data set and I would like to learn the weighted combination of the detectors…
Eric
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Feature selection for each class in image classification

I have to do an image classifier (based on already extracted features) on a big db of images, at the same time i have to retrieve the most relevant features for each class. I found a lot of papers on the internet talking about "feature selection"…
accand
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Feature selection using PCA

Data set consists of N elements and K variables. Using PCA I can reduce the number of variables, but how to check which from K of variables provided the most informations? For example I have data set like this: 1 1 1 2 2 2 1 4 3 3 2 11 1 1 2 7 2 2 3…
veeveeoor
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Classification using R in a data set with numeric and categorical variables

I'm working on a very big data-set.(csv) The data set is composed from both numeric and categorical columns. One of the columns is my "target column" , meaning i want to use the other columns to determine which value (out of 3 possible known values)…
mosh
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Classification of new instances in weka

In our training set, we performed feature selection (ex. CfsSubsetEval GreedyStepwise) and then classified the instances using a classifier (ex. J48). We have saved the model Weka created. Now, we want to classify new [unlabeled] instances (which…
Dids
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Text classification with neural network

Can someone tell me how can I classify some text messages using neural network.? Is there any examples? how do I preprocess text messages to train the neural network? Thanks
Thusitha Thilina Dayaratne
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Conceptual queries on retrieving 'visually similar' images: Dense SIFT or other descriptor?

I am posting 3 images of my dataset to show how my image visually looks: http://s1306.photobucket.com/user/Bidisha_Chakraborty/library/?page=1 I am using VLFFeat DSIFT implementation. I am using per descriptor 4 orientations instead of 8. So in my…
Bidisha Chakraborty
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OpenLayers Click on selected Feature triggering function

I am using OpenLayers to draw point features on a map with a cluster strategy. strategy = new OpenLayers.Strategy.Cluster(); clusters = new OpenLayers.Layer.Vector("Clusters", { strategies: [strategy], …
manilly
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Strategies for handling nominal values with numerical attributes

I'm using a data set that consists of mostly nominal values from SFDC (e.g. EE Names, Title, Role, Lead Source, Account Name, etc.) and am trying to correlate the features to a boolean class of whether a Sales Lead was converted to a Sales Contact.…
mwoods
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