Talk:Support vector machine

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There is not enough information about solving SVMs. There is only the mention that it's a quadratic optimization problem. A discussion of solving and a brief example would be very helpful. 216.145.54.158 21:59, 4 August 2006 (UTC)


Hey - I dont think that kernel PCA should redirect here? Sort of like redirecting "dogs" to "Animals" It probably needs its own article.--137.215.9.20 09:07, 26 July 2006 (UTC)


Hello! I have a comment about the first sentence, which says "A SVM is a <blank>", and <blank> has been either "statistical classification model" and "supervised learning method" lately. I'm in favor of the former because it situates SVM in a very large group of related methods from both conventional statistics and machine learning. "Supervised learning" is deficient on two counts -- s.l. also includes regression as well as classification, and it suggests only a link to machine learning and not conventional statistics. So I'd like to hear what other people have to say. Happy editing, Wile E. Heresiarch 02:35, 29 Apr 2004 (UTC)

Yes, indeed, classification is more specific than supervised learning. However, there are both classification and regression forms of a support vector machine. The latter is often called Support Vector Regression (SVR). I added a discussion of SVR to this article, although it is difficult for laypeople to understand. Anyway, I think that supervised learning is a more accurate description. The article supervised learning is much less stubby than classification, too.
To me, machine learning is statistics, so I don't have a preference for "supervised learning" over "classification" on that basis. -- hike395 04:46, 29 Apr 2004 (UTC)

Hmm. Not quite the way I'd put it. However, I haven't got my references on me at the moment, so I can't come up with a precise description. -- 213.253.39.90


Do SVMs have to be non-linear? I thought they could be either linear or non-linear. -- Oliver PEREIRA 13:18 Jan 26, 2003 (UTC)

No. See if my new edit makes you happier. By the way, does anyone know why they're called "machines"? Nobody seems to call older machine learning techniques (e.g. the perceptron, feed-forward networks, etc.) "machines". --Ryguasu 00:13 Apr 2, 2003 (UTC)

According to Vapnik (The Nature Of Statistical Learning Theory, p. 133) they are non-linear: The Support Vector (SV) machine implements the following idea: it maps the input vectors x into a high-dimensional feature space Z through some nonlinear mapping, chosen a priori. In this space, an Optimal separating hyperplane is constructed. To be strict a so-called linear SVM is an optimal hyperplane (it has support vectors, but is not a support vector machine), although many authors ignore this. --knl 15:57, 28 Aug 2004 (UTC)

Fast and lightweight? As compared to what? (Sitting in front of machine that's spent 3 days on a linearly separable dataset C4.5 takes a few minutes to chomp through). User:Iwnbap


Don't forget Sequential Minimal Optimization (SMO) [1]


As someone who doesn't know SVM very well yet, I say this article could really use a picture. The article is technically correct, but not enlightening to a newbie. Someone drew me a picture with two classes (+ and -), some separating planes (i.e., a 2-d example) and explained that many cases not near the planes are often thrown away. I thought it helped a lot. If I knew SVM well enough, I would upload and label the picture. Maybe I will if I learn more. dfrankow 03:54, 3 March 2006 (UTC)

Hope the picture I added makes it more clear AnAj 19:23, 15 June 2006 (UTC)
I can not see the picture in the article. Is the link wrong? —The preceding unsigned comment was added by 84.216.75.78 (talk • contribs) .
Apparently there was something wrong with the thumbnail cache. I purged it and now it shows correctly on all thumbnail sizes at least for me. AnAj 09:04, 13 August 2006 (UTC)

[edit] How to add a Loss-Matrix to SVM

Maybe anybody can point out how to incoperate a Loss matrix into the svm framework. I've been looking for this information on various places and I think this would add some great value to the article.