Questions on the cluster analysis functions of Mathematica, including the Hierarchical Clustering Package.

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8
votes
1answer
280 views

FindClusters for 3D Pancake/Platelet Shapes

I'm looking to properly cluster a dataset of roughly 3 million data points in 3-space. The shapes form closely spaced "clusters" that resemble pancakes. Here is a downsampled dataset: ...
16
votes
4answers
1k views

Clustering a set of points

I have a set of 2D points in the square defined by {-1, -1} and {1, 1}. These points typically form compact groups. I need to ...
7
votes
2answers
383 views

Different highlight for each cluster in DendrogramPlot

Is there any way to have each cluster in the DendrogramPlot highlight in a different color? I've tried the obvious way but it doesn't work: ...
4
votes
1answer
184 views

How does DistanceFunction work with images in ClusteringComponents?

Does anyone know the syntax to DistanceFunction? I am trying to define my own function to use with ClusteringComponents; e.g., ...
3
votes
1answer
352 views

Plotting reordered clusters with different colors and joined lines

I would like to show how typical days of energy load (found through clustering of a years worth of data) are spread throughout a year in a single graph with a color for each 'typical day' (or ...
8
votes
2answers
407 views

Why doesn't FindClusters find any clusters in this case?

I am trying to use FindClusters to segment data points into similar numbers but so far I couldn't get it work for this example: ...
3
votes
2answers
240 views

Which group of points connects more strongly?

I have two groups of points, and the lenth of them may be different.I want to know which group of points connects more strongly, are there any existing algorithms for this? Here are two groups of ...
16
votes
2answers
496 views

Cluster a signal into areas of equal intensity

Introduction I have a greyscale photograph that I want to partition into areas of equal intensity. This means, that the integral over each partition should be (roughly) equal. There is no unique ...
3
votes
1answer
132 views

How to give ClusteringComponents initial values?

I came across a variant of k-means that adds a algorithm to select good starting values called k-means++. ...
11
votes
4answers
1k views

data clustering

I have some data set which i would like to partition into 3 groups a:set 1 b: set 2 c: background. I use FindClusters[] function but as you can see (after ...
4
votes
2answers
658 views

Clustering a bivariate data set with Mathematica

I need to partition a bivariate data set into predetermined "n" clusters and, at the same time, to fix the centroid position of each cluster. Is the ...
13
votes
1answer
835 views

Visualize cluster distances in DendrogramPlot

I want to perform a cluster analysis using the HierarchicalClustering package. Is there a way to display the inter-cluster distances in a dendrogram plot? An ...
26
votes
4answers
5k views

K-means clustering

In MATLAB, there is a command kmeans() that divides an array into $k$ clusters and calculates the centroid of each cluster. Is there any command in Mathematica to ...
6
votes
1answer
531 views

Clustering adjacent points in 2D

I need to find all clusters of adjacent white points in a binary image. By term "adjacent" I mean that coordinates of two points differ by no more than 1 (i.e. the points ...
6
votes
1answer
215 views

Stopping Agglomerative clustering under a condition in Mathematica

How do I instruct Agglomerative clustering to stop/NOT merging two particular clusters if the distance between the two clusters is larger than a threshold value? I know that we can implement a custom ...
5
votes
2answers
494 views

Custom distance metric for agglomerative clustering in Mathematica

Is it possible to have a custom distance metric defined to determine the distance between two clusters in Agglomerative clustering in Mathematica? I have a 3 dimension data with string values along ...
5
votes
4answers
553 views

Identifying subsets with minimal standard deviation

Consider the following: ...
11
votes
1answer
477 views

Cluster analysis returns questionable results

A few weeks ago I ran a cluster analysis on some economic data and (unfortunately only) now I found out that some results do not make sense. For instance I analyzed the development of unemployment ...
29
votes
4answers
2k views

Clustering of space-time data

Below is an example of a gaze sequence I recorded during a 3 seconds display. That is, where the eye was at every millisecond. While we should have 3000 points, we are missing some due to blinking. ...