R Tutorial: What is cluster analysis?

Want to learn more? Take the full course at https://learn.datacamp.com/courses/cluster-analysis-in-r at your own pace. More than a video, you'll learn hands-on coding & quickly apply skills to your daily work. --- Hi, my name is Dima and I am very excited to have you join me in learning all about cluster analysis in R. Cluster analysis is a form of data exploration, and the key to harnessing its power lies in understanding how it works. So, in this course you won't just learn the tools necessary to perform cluster analysis - that's the easy part - I will work with you to build the intuition behind the underlying methods. But, before we get to the how, let's take a moment to discuss, what is clustering? No matter whether you are working with medical data, retail data, or sports data, as a data scientist you are often presented with a bunch of data that you need to make sense of. To understand what clustering is, let's put aside the details of our data and instead focus on the toy example where the data is represented as a matrix containing entries of card suits. To look at it another way, this matrix is composed of rows containing our observations and columns that tell us something that we measured across these observations. We will refer to these columns as the features of our observations. In cluster analysis, we are interested in grouping our observations such that all members of a group are similar to one another and at the same time they are distinctly different from all members outside of this group. Imagine in this example we performed a cluster analysis to find which observations are similar to one another based on what suit appears in each column. In this case, we identified three groups and colored the observations accordingly. To better see these patterns, let's re-organize our observation into their respective colored clusters. Here we can start to see clear patterns that emerge. Fundamentally, this is how cluster analysis works. Or to put it a