Unsupervised part in machine learning for group similarities. Fully Explained K-means Clustering with Python

K-means clustering is a very simple and insightful approach to make inferences from the grouped clusters’ similarities. It is unsupervised learning in which we don’t have output labels. If we talk about regression, classification and clustering algorithms, the regression is mainly used for predicting something based on the growth of something, weather forecast, etc based on mainly numerical values. Other side, learners are sometimes confused a little bit in classification and clustering, the simple difference is clustering doesn’t have label output but rather works on similarities and classification works with known output labels to make them in the group.Clustering algorithms are less complex than classification. While in classification we train and test out data and in clustering, we don’t need it. The points to be noticed for not using train-test split in clustering.

- We analyze based on data points similarities.The testing error will be more on putting a large number of clusters i.e. the centroid of each cluster.K-means metrics choose the cluster in such a way that inertia should be low, here inertia means the sum of squared of data points within clusters (WCSS).

We should not jump fast on the number of clusters to be used in the algorithm. There are some points we have to observe first.

- The inertia thinking is very fast and non-reliable i.e. it assumes that group similarities are isotropic and convex. The isotropic means a uniform shape and convex means the data points are more in the middle and less on the boundary of the cluster. But, the real-world data are not working on these assumptions, their shape and uniformity changes, it can be irregular shape, elongated on one side.Normalization of data set values. It means the low value of inertia is good. But in the real world, we measure the data points distance for cluster (either by Euclidean or Manhattan distance measurement) can get inflated. A term used for this is “curse of dimensionality”. If there are high variations in data points we should do PCA and normalization of data points.

programming machine-learning artificial-intelligence data-science python

Practice your skills in Data Science with Python, by learning and then trying all these hands-on, interactive projects, that I have posted for you.