Questions tagged [support-vector-machines]

For questions about using support vector machines (SVMs), models that aim to separate a given data space using hyperplanes.

Filter by
Sorted by
Tagged with
5
votes
1answer
155 views

How to train a model to classify object trajectories?

I have a tracker that outputs the trajectory $(x,y,z)$ of an object (e.g., a can). I want to use these trajectories to train a classifier (i.e., SVM) in order to infer the activity that the person ...
0
votes
1answer
38 views

Support Vector Machines to use after Classification?

I'm a little bit about the SVM. I'm actually understanding for which purpose Support Vector Machines are used. The aim is to find the biggest (best) hyperplane between two different data clusters. The ...
0
votes
0answers
66 views

approximation of nonlinear time-dependent system with history

I have two time-dependent coupled equations. One of which is several orders of magnitude more computationally demanding than the other. I am trying to use machine learning to reproduce the behavior of ...
3
votes
1answer
1k views

How to train an L2-regularized L1 Hinge Loss SVM using vowpal wabbit?

I'm trying to train an L2-regularized L1-hinge loss SVM using vowpal-wabbit. I use the following commands to train and test on the splice dataset: ...
10
votes
2answers
3k views

Do RBF kernel matrices tend to be ill-conditioned?

I use RBF kernel function to implement one kernel based machine learning algorithm(KLPP), the resulting kernel matrix $K$ $$K(i,j)= \exp\left({\frac{-(x_{i}-x_{j})^2}{ \sigma_{m}^2}}\right)$$ is ...
6
votes
1answer
185 views

Support Vector Machines as Neural Nets?

This is more of a conceptual question. I have learned about Neural Nets, and I have some clue as to how Support Vector Machines work. I read somewhere however that given the appropriate kernel (is ...
0
votes
1answer
69 views

SVM Math Question

I'm studying support vector machines and came across this paper. The following equation doesn't make sense to me, especially the part with the 0 ∀i. Any help understanding the basics of SVMs? yi * (...
6
votes
1answer
180 views

Confusion related to convexity and concavity of a function

I was reading this paper http://www.ist.temple.edu/~vucetic/documents/wang11kdd.pdf related to adaptive multi-hyperplane machine for non linear classification In that paper, they have mentioned about ...
2
votes
1answer
43 views

Why do some known kernel functions manage to achieve linear separation in feature space?

I'm currently learning the maximal margin classifier with kernels, and I'm wondering - why do they work? In which cases do they work best? I'm especially interested in the RBF and polynomial kernels, ...
7
votes
2answers
211 views

Why is the Dual problem preferred for Maximal Margin Classification?

The primal problem is $$\min_{w,b}\frac{1}{2}w^Tw$$ $$s.t. f_i(w)=1-y_i(w\cdot x_i+b)\leq0$$ Where $y_i=\pm1$. Instead of using Gradient Descent directly, the dual is usually solved: $$\max_{\...
1
vote
1answer
72 views

Confusion related to svm optimization

I was reading thispaper related to kernel SVM. It states Support Vector Machine (SVM) (Cortes and Vap- nik, 1995) as the state-of-the-art classification algo- rithm has been widely applied in ...
0
votes
1answer
56 views

Confusion related to convexity of a problem

I was reading this paper related to Multiclass Classification with Multi-Prototype Support Vector Machines - paper However, I am having difficulty in understanding why they have mentioned the ...
10
votes
2answers
4k views

Calculating Lagrange coefficients for SVM in Python

I'm trying to write a full SVM implementation in Python and I have a few issues computing the Lagrange coefficients. First let me rephrase what I understand from the algorithm to make sure I'm on the ...