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Questions tagged [libsvm]

LIBSVM is a library for Support Vector Machines

LIBSVM is an integrated software for support vector classification, (C-SVC, nu-SVC), regression (epsilon-SVR, nu-SVR) and distribution estimation (one-class SVM). It supports multi-class classification. It comprises of both C++ and Java sources, and interfaces to several commonly used languages, such as Python, MATLAB, R, Ruby, Perl, PHP and Haskell.

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What is the relation between the number of Support Vectors and training data and classifiers performance?

I am using LibSVM to classify some documents. The documents seem to be a bit difficult to classify as the final results show. However, I have noticed something while training my models. and that is: If my training set is for example 1000 around 800…
Hossein
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How to do multi class classification using Support Vector Machines (SVM)

In every book and example always they show only binary classification (two classes) and new vector can belong to any one class. Here the problem is I have 4 classes(c1, c2, c3, c4). I've training data for 4 classes. For new vector the output should…
mlguy
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python csv2libsvm.py: AttributeError: '_csv.reader' object has no attribute 'next'

I want to convert a csv file into sparse format file with csv2libsvm.py (https://github.com/zygmuntz/phraug/blob/master/csv2libsvm.py). The CSV file contains 37 attributes + the label (last column). it doesn't contain header or index. Exp of the 1st…
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Pointers to some good SVM Tutorial

I have been trying to grasp the basics of Support Vector Machines, and downloaded and read many online articles. But still am not able to grasp it. I would like to know, if there are some nice tutorial sample code which can be used for…
Alphaneo
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What is the difference between SVC and SVM in scikit-learn?

From the documentation scikit-learn implements SVC, NuSVC and LinearSVC which are classes capable of performing multi-class classification on a dataset. By the other hand I also read about that scikit learn also uses libsvm for support vector…
tumbleweed
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What's the difference between LibSVM and LibLinear

libsvm and liblinear are both software libraries that implement Support Vector Machines. What's the difference? And how do the differences make liblinear faster than libsvm?
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A few implementation details for a Support-Vector Machine (SVM)

In a particular application I was in need of machine learning (I know the things I studied in my undergraduate course). I used Support Vector Machines and got the problem solved. Its working fine. Now I need to improve the system. Problems here…
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An example using python bindings for SVM library, LIBSVM

I am in dire need of a classification task example using LibSVM in python. I don't know how the Input should look like and which function is responsible for training and which one for testing Thanks
Hossein
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using precomputed kernels with libsvm

I'm currently working on classifying images with different image-descriptors. Since they have their own metrics, I am using precomputed kernels. So given these NxN kernel-matrices (for a total of N images) i want to train and test a SVM. I'm not…
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Under what parameters are SVC and LinearSVC in scikit-learn equivalent?

I read this thread about the difference between SVC() and LinearSVC() in scikit-learn. Now I have a data set of binary classification problem(For such a problem, the one-to-one/one-to-rest strategy difference between both functions could be…
Sidney
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How to obtain features' weights

I am dealing with highly imbalanced data set and my idea is to obtain values of feature weights from my libSVM model. As for now I am OK with the linear kernel, where I can obtain feature weights, but when I am using rbf or poly, I fail to reach my…
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Know any good c++ support vector machine (SVM) libraries?

Do you know of any good c++ svm libraries out there I tried libsvm http://www.csie.ntu.edu.tw/~cjlin/libsvm/ but so far I'm not flabbergasted. I have also heard of SVMLight and TinySVM. Have you tried them ? Any new players ? Thanks !
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Retraining after Cross Validation with libsvm

I know that Cross validation is used for selecting good parameters. After finding them, i need to re-train the whole data without the -v option. But the problem i face is that after i train with -v option, i get the cross-validation accuracy( e.g…
lakshmen
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SVM equations from e1071 R package?

I am interested in test the SVM performance to classify several individuals into four groups/classes. When using the svmtrain LibSVM function from MATLAB, I am able to get the three equations used to classify those individuals among the 4 groups,…
Manuel Ramón
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How to prepare data into a LibSVM format from DataFrame?

I want to make libsvm format, so I made dataframe to the desired format, but I do not know how to convert to libsvm format. The format is as shown in the figure. I hope that the desired libsvm type is user item:rating . If you know what to do in the…
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