What are Support Vector Machines?
Support Vector Machines (SVMs) are a type of machine learning algorithm typically used for classification and regression analysis in data science. They are built on the concept of decision planes that define decision boundaries. A decision plane is one that separates different sets of objects having different class memberships.
How does SVM work?
In simple terms, SVM draws a line or a hyperplane between data of two classes in such a way that the distance from the nearest points in each of the two groups is maximized. These nearest points are known as “support vectors”. Hence, the algorithm is named as Support Vector Machine.
Key Elements of SVM
- Hyperplane: This is the decision boundary that separates different classes. It is chosen to maximize the distance from the closest points of each class.
- Support Vectors: These are the data points that lie closest to the decision boundary or the hyperplane. They are the points that if moved, would alter the position of the dividing hyperplane.
- Margin: This is the gap between the two lines on the closest class points. SVM tries to maximize this distance.
Why use SVMs in Web Development?
SVMs are useful in various aspects of web development and design. Here’s why:
- Text and Hypertext Categorization: SVMs allow text and hypertext for automated document classifications. They are also used for web page ranking for internet search engines.
- Image Classification: SVMs are also used for identifying and classifying images, which can be useful in web design and user interface configurations.
- Hand-written Character Recognition: This can be particularly useful in designing CAPTCHA systems for websites.
Pros and Cons of SVMs
Like any machine learning algorithm, SVMs come with their pros and cons.
- SVMs deliver a unique solution, since the optimality problem is convex. This is a big advantage over Neural Networks, which can have multiple solutions associated with local minima and for this reason may not be robust over different samples.
- SVMs have generalization in practice, the risk of overfitting is less in SVMs.
- The biggest limitation of the support vector approach lies in choice of the kernel.
- A second limitation is speed and size, both in training and testing.
In conclusion, Support Vector Machines offer a powerful method for general purpose supervised machine learning, and have particular strengths for handling complex but small- or medium-sized datasets.