Join Curt Frye for an in-depth discussion in this video How do you identify clusters?, part of Up and Running with Excel Cluster Analysis.
…In the previous movie, I gave you a verbal…overview of what the cluster analysis process looks like.…In this movie, I'll make that presentation a bit more visual.…So for cluster analysis, let's say that you have…data that is visualized on an XY scatter chart.…When you analyze your data, it looks like there…might be two separate groups, so you add two centroids.…These centroids will be moved around and used…to determine which points are part of which group.…The next step is to calculate the distance from each point to each centroid.…
For this example, let's focus on the point at…the top left and the point at the bottom right.…There are many different ways to measure distance, but in this case, I'll…use what's called the Euclidean distance, and it's based on the Pythagorean Theorem.…So you calculate the vertical distance between a point and a centroid.…So, for example, that might be a, then the horizontal distance, that would be b,…and what you're trying to calculate is the…hypotenuse of this right triangle, which is c.…
- What is clustering?
- Setting up your Excel table
- Creating a list of centroids
- Identifying the closest centroid
- Updating centroids using averages
- Automating updates with macros
- Analyzing your data in Excel
- Visualizing data in a chart