Calculating Clusters

The Cluster Dialog allows you to calculate clusters in postprocessing plots.

  1. From the menu bar, select Edit > Cluster analysis > Clusters.

  2. Select the dimensions to calculate the cluster with.

  3. Select a cluster algorithm.

    • Centroid

      The centroid method is an agglomerative cluster algorithm which joins clusters based on the euclidean distance of its means until a specified minimal distance is reached. You can set the minimum distance between the means of two clusters.

    • Single Linkage

      The single linkage method is an agglomerative cluster algorithm which joins clusters based on the shortest euclidean distance between them. The shortest distance between two clusters is the minimum distance between two elements of the two clusters. You can set the minimum distance.

    • K-means

      K-means clustering is a centroid-based method that partitions n elements into k clusters in which each element belongs to the cluster with the nearest mean (cluster center), serving as a prototype of the cluster. It minimizes within-cluster variances. This results in a partitioning of the data space into Voronoi cells. You can set the number of clusters.

  4. To find a suitable distance setting for the Centroid or the Single linkage method:

    1. Select the Pre cluster calculations check box.

    2. Click Calculate circular distances.

      The mean and standard deviation of all smallest distances between two designs are calculated. The distances are shown as histogram.

    3. To adjust the minimum distance of the cluster method, change the sigma factor below the plot.

  5. Click Calculate cluster.

    After the cluster calculation, the number of obtained clusters is shown.

  6. To show the results of the cluster analysis in the postprocessing, click Apply or OK.

  7. To clear the result of the cluster analysis, click Delete cluster. When you next click Apply or OK, the cluster results are also cleared in the postprocessing.