# Compare Clusters ## What is Compare clusters? Compare clusters is a tool to identify the optimal number of clusters for K-means Clustering using the Davies-Bouldin index. The Davies-Bouldin index is a measure of cluster quality where a lower value indicates better clustering, i.e., the separation between points within the clusters is low (tight clusters) and separation between clusters is high (distinct clusters). ## Running Compare clusters We recommend normalizing your data prior to running *Compare clusters*, but the task will run on any counts data node. * Click the counts data node * Click the **Exploratory analysis** section of the toolbox * Click **Compare clusters** * Configure the parameters * Click **Finish** to run (Figure 1)

Figure 1. Compare clusters configuration dialog

The parameters for *Compare clusters* are the same as for *K-means* *clustering*. ## Compare clusters task report The *Compare clusters* task report is an interactive line chart with the number of clusters on the x-axis and the Davies-Bouldin index on the y-axis (Figure 2).

Figure 2. The Compare clusters task report shows the Davies-Bouldin index for each number of clusters.

The *Compare clusters* task report can be used to run *K-means clustering.* * Click a point on the plot to select it or type the number of clusters in the text box *Partition data into clusters* Selecting a point sets it as the number of clusters to partition the data into. The number of clusters with the lowest Davies-Bouldin index value is chosen by default. * Click **Generate clusters** to run *K-means clustering* with the selected number of clusters A *K-means clustering* task node and a *Clustering result* data node are produced. Please see our documentation on K-means Clustering for more details. ## Additional Assistance If you need additional assistance, please visit our support page to submit a help ticket or find phone numbers for regional support. --- # Agent Instructions: Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter: ``` GET https://help.partek.illumina.com/partek-flow/user-manual/task-menu/exploratory-analysis/compare-clusters.md?ask= ``` The question should be specific, self-contained, and written in natural language. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.