Questions tagged [cluster-analysis]

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

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29
votes
4answers
8k 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 ...
12
votes
2answers
1k views

Creating Identification/Classification trees

I have data given in following format; from which I need to create identification/classification trees (three different trees from three different criterion, that is average disorder, gain ratio and ...
0
votes
1answer
197 views

FindClusters versus ClusteringComponents

[Cross-posted on the Wolfram Community.] I just found out that there's a difference in the number clusters retrieved when using FindClusters and ...
25
votes
4answers
2k views

Generating an “average curve” from a dense set of “semicontinuous curves” which clear trends

This question is related to a previous one of mine: Partitioning a superset of coordinates into subsets that generate continuous curves, where the challenge was to partition a data set into two ...
13
votes
1answer
1k 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 ...
33
votes
4answers
3k 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. ...
9
votes
2answers
334 views

Partitioning a superset of coordinates into subsets that generate continuous curves

Consider the data set corresponding to recorded trajectories for a particle: ...
13
votes
1answer
347 views

User-defined distance functions in FindClusters

I am trying to use FindClusters to segment data points into two special parts data ...
6
votes
3answers
1k views

Finding connected components in an array

I have an $w\times h$ array with non-negative integers. I wish to partition the set of coordinates $(c,r)$ with $1\leq c \leq w$ and $1\leq r \leq h$, in subsets, so that each subset corresponds to a ...
17
votes
4answers
2k 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 ...
16
votes
2answers
608 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 ...
11
votes
4answers
2k 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 ...
11
votes
4answers
705 views

Morphological Components with periodic boundary conditions

I would like to find the connected(with periodic boundary conditions) components in a large binary matrix. What I've tried, and it does a fair job is: ...
14
votes
4answers
631 views

How to split data into clusters based on fitting to function

I have data which looks somewhat like this: On the picture, you can see that the data can be described by 2 linear functions - if you manage to split it into 2 groups, each can easily be fitted with <...
8
votes
1answer
176 views

How to get `FindCurvePath` to return only one list

As you can see below, FindCurvePath returns only a part of the list, resulting in a partial interpolation. I would like to interpolate all the points. Complete ...
5
votes
1answer
2k views

Clustering 3D Data Points on a Periodic Cubic Grid

I have a set of 3D data points on a cubic grid. The data can be downloaded from here https://skydrive.live.com/redir?resid=F96524B72DCD75FB!14240 and read into a variable ...
5
votes
2answers
181 views

Inexplicable results from ClusteringComponents Agglomerate in version 11.1

I have data like this: data = {5, 12, 18, 19, 20, 23, 24, 26}; On Mathematica 11.1, clustering produces a variable final choice of clusters. For example: ...
4
votes
1answer
228 views

How to rapidly find the nearest pairs of points in different clusters

Background For speed up this question or this question,I have such need. Current try: Suppose I have $3$ clusters of points: ...
4
votes
3answers
346 views

make specific cluster

I have set of coordinates. I want to make clusters in which every point is within 1.5 distance unit of it's neighbor. ex of point coordinates: ...
3
votes
1answer
429 views

Hierarchical clustering: convert Mathematica cluster hierarchy to NEWICK format

Can anyone tell me a clever way to convert the hierarchical clustering object, created, say, by Agglomerate or DirectAgglomerate ...
6
votes
1answer
117 views

Why does FindClusters put closer points into different clusters?

Bug introduced in 11.3 or earlier and persisting through 12.0 Bug isn't present in version 8.0.4 I am trying to do clustering and then obtained a plot as below:- ...
2
votes
2answers
148 views

How to form multiple clusters of given size from a set of points?

Let us consider a 2 dimensional space. There are 100 points in it. So, each point has its $x$ and $y$ coordinates. I want to form 10 clusters. Each cluster has 10 points. How can I form such ...
7
votes
0answers
124 views

FindCluster only finds cluster “with a little help”

Currently I made some slides to illustrate clustering. As an example I made a point set of two clusters: ...
5
votes
2answers
255 views

Agglomerate output to Graph

I'm using the HierarchicalClustering package to cluster some data. So let's say I have this: ...
3
votes
1answer
97 views

Finding the size of connected clusters with specific patterns in an array

I have a $w \times h$ array with either $-1$ or $+1$. I wish to monitor the size of the largest connected clusters with specific patterns that occur during a Monte Carlo simulation, i.e., a ...
2
votes
0answers
131 views

How do I detected linear clusters of points in 3D data?

I have a list of 3D points. ...
2
votes
1answer
87 views

Partitioning a list in n sublists with constrains in their sums

Is there a way to put cluster level limits on clusters? For example, if I run: FindClusters[{1, 2, 3, 4, 4, 6, 7, 10}] I get back two lists, ...
1
vote
1answer
38 views

Building a nine - region cluster chart but, getting inaccurate plot-legend when empty subregions are present

This is a follow up question to the one submitted at the following: Stack exchange Link I quickly get to the subject: ...
0
votes
1answer
123 views

How to segment an image based on MeanEuclideanDistance?

Consider an image (img) as Now I have partitioned the image using the following command parts = ImagePartition[img, 32]; ...