The only requirement to be called an unsupervised learning strategy is to learn a new feature space that captures the characteristics of the original space by maximizing some objective function or minimising some loss function.
Therefore, generating a covariance matrix is not unsupervised learning, but taking the eigenvectors of the covariance matrix is because the linear algebra eigendecomposition operation maximizes the variance; this is known as PCA.
Unsupervised learning
Some of the most common algorithms used in unsupervised learning include:
group data points that are close (or similar) to each other
identify such groupings (or clusters) in an unsupervised manner
Unsupervised learning
A cluster is represented by a single point, known as centroid (or cluster center) of the cluster
Centroid is computed as the mean of all data points in a cluster
Cluster boundary is decided by the farthest data point in the cluster
Application of Clustering
Example 1: groups people of similar sizes together to make “small”, “medium” and “large” T-Shirts.
Tailor-made for each person: too expensive
One-size-fits-all: does not fit all.
Example 2: In marketing, segment customers according to their similarities
To do targeted marketing.
Example 3: Given a collection of text documents, we want to organize them according to their content similarities,
To produce a topic hierarchy
Thank you! Contacts Khabibullo Nosirov, Phd Project Manager, Head Of The Department Tashkent University Of Information Technologies named after Muhammad Al-Khwarizmi Radio And Mobile Communications Faculty 100084, Amir Temur 108, Tashkent, Uzbekistan n.khabibullo1990@gmail.com +998 99 811 57 62 (WhatsApp) +998 90 911 57 62 (Telegram) www.tuit.uzwww.spacecom.uzwww.intras.uz