# Questions tagged [clustering]

Cluster analysis or clustering is the task of grouping a set of objects in such a way that objects in the same group (called a cluster) are more similar (in some sense or another) to each other than to those in other groups (clusters). It is a main task of exploratory data mining, and a common technique for statistical data analysis, used in many fields, including machine learning, pattern recognition, image analysis, information retrieval etc.

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### Mine webshop history for clusters

I've no experience in data science so this will be one of those questions... I have data from >100k purchases made via a webshop regarding a catalogue of around >100 items. The history of purchases ...
2k views

### The implementation of overlapping clustering (NEO-K-Means)

I am researching on overlapping clustering (Clusters are non-disjoint).I found that Neo-K-Means is probably the state-of-the-art now.But, when I tried implementing the algorithm with the multi-label ...
514 views

### Details of the k-means++ algorithm that is used to seed k-means

Regard to K-Means++ algorithm, which is an algorithm for choosing the initial values (or "seeds") for the k-means clustering algorithm. K-Means++ algorithm in Wikipedia The exact algorithm is as ...
977 views

### Definition - center of the cluster with non-Euclidean distance

I have cluster consisting of two points and I am working with non-Euclidean distance. I wonder if it is appropriate to talk about center of cluster in this case and how we can interpret it? We can ...
9k views

### What is the difference between affinity matrix eigenvectors and graph Laplacian eigenvectors in the context of spectral clustering?

In spectral clustering, it's standard practice to solve the eigenvector problem $$L v = \lambda v$$ where $L$ is the graph Laplacian, $v$ is the eigenvector related to eigenvalue $\lambda$. My ...
41k views

### Calculating KL Divergence in Python

I am rather new to this and can't say I have a complete understanding of the theoretical concepts behind this. I am trying to calculate the KL Divergence between several lists of points in Python. I ...
1k views

### Cluster Similar Images into Folders

I wasn't sure where to ask this question so forgive me if the question seems out of place (and please guide me where to ask it !) I have an archive of 9GAG images and I want to Cluster them based on ...
160 views

### Can k-means clustering get shells as clusters?

Imagine you have $k$ classes. Every class $i$ has points which are follow a probability distribution, such that their distance to 0 is $i$ in mean, but this distance follows a normal distribution. The ...
106 views

### How to cluster Houses on the basis of similarity of features+location?

I have a dataset of houses like this: HouseID Latitude Longitude PriceIndex 1 1.4 103.120 1.21 2 1.42 103.112 2.01 I want to ...
1k views

### How to evaluate the clustering result when cluster numbers are not equal to data set class

When apply clustering algorithm with the multi-class data set and class numbers are not equal to the result cluster numbers(For example , When we use K-Means algorithm by setting K = 3 apply with "...
111 views

### Which algorithm would you use for text categorisation using clustering? [closed]

If you are asked to do text categorization using clustering. Which algorithm would you use and why?
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### Canopy clustering implementation in Python

As far as I understand, canopy clustering preprocessing procedure is not implemented in scikit-learn. Is there a python library for this?
91 views

### Introducing weights into spectral clustering

Suppose I have a data set with points $x_i$ and a dissimilarity measure $d_{ij}$ between each pair, as well as a weight $w_{ij}$ that qualifies the quality of this dissimilarity. I have two problems: ...
17 views

### Handling covariance matrices of changing size

In the context of a gaussian mixture model, we can place a prior on the covariance of the cluster means. In an infinite GMM, the problem then arises that changing the number of clusters also changes ...
19k views

### Clustering for mixed numeric and nominal discrete data

My data includes survey responses that are binary (numeric) and nominal / categorical. All responses are discrete and at individuals level. Data is of shape (n=7219, p=105). Couple things: I am ...
77 views

### How do I learn experimental methodology? When is it relevant?

I just graduated in Computer Science, with a very theoretical background but without any kind of Data Science or Artificial Intelligence experience, and I working on my own to discover those two ...
170 views

### What are references explaining Hugo Steinhaus early “data science” work?

Historical background: Hugo Steinhaus can be considered as an early father of data science. He authored the paper Sur la division des corps matĆ©riels en parties, Bulletin de lāAcadĆ©mie Polonaise des ...
134 views

### Agglomerative Clustering Stopping Criteria

I am trying to implement section 3.4 of paper Predicting Important Objects for Egocentric Video Summarization where they have created a distance matrix of frame histograms. In short, let say ...
212 views

### Attribute discretization

I have a dataset where I need to explore using unsupervised technics (clustering and association rules). What are the best strategies to discretize the numeric attributes? Also, does this (attribute ...
300 views

### tf-idf clustering

I have over a million text documents that I would like to cluster. I used tf-idf modeling and term vector cosine for identifying similar documents in the corpus, which appeared to work well. Some ...
68 views

### Clustering related areas with k-means

I am trying to cluster related areas of knowledge based in publications.For example a researcher has 3 keywords in a paper, in another paper he has 5 keywords, but 3 keywords are the same in the both ...
101 views

### Clustering with constraints

I have a dataset of this form: chrX posX labelX where chrX refers to the chromosome number, ...
429 views

### How should clickstream data be prepared before user segmentation can be performed?

I'm interested in doing segmentation/clustering of users in clickstream data and am looking for some good suggestions about how to go about it. Lets say my data consists of observations made up of ...
106 views

### Devices behavior in one continuous variable vs events rate

I have devices on which I have time series data of one continuous variable. I have to evaluate the relation between the profile of that variable on those devices and "events". Those events are given ...
164 views

### How to create clusters of position data?

I am asking this question because the previous one wasn't very helpful and I asked about a different solution for the same problem. The Problem I have lateral positions, ...
185 views

### Clustering large number of strings based on tags

I have string representations of text written by users in the form of parts of speech tags like so: $NNDN,OVDANPN,PNVRV,^^V,^^!$^OV and ...
139 views

### Is Minimax Linkage a Lance-Williams hierarchical clustering?

I found the following article on "Hierarchical Clustering With Prototypes via Minimax Linkage". It is stated in Property 6 that Minimax linkage cannot be written using LanceāWilliams updates. A ...
161 views

### Classification problem where one attribute is a vector

Hello I am a layman trying to analyze game data from League of Legends, specifically looking at predicting the win rate for a given champion given an item build. Outline A player can own up to 6 ...
1k views

### How to rank documents using Bag of words approach

I want to cluster the documents I get for Google scholar search using the Bag of words model. I thought of using Java as the language. Assume for the keyword k, Google scholar gives me 50 results. If ...
45 views

### Best way to fuse clusters smaller than a certain size in a distributed way?

I have X clusters of size (n1,n2...,nX) and I want to fuse small clusters with less than T members with the nearest adjacent cluster i.e. the nearest neighboring cluster. The problem is when I've got ...
637 views

### Cluster directed graph into DAG

I am looking for an algorithm that clusters a directed graph into a set of clusters that form a directed acyclic graph. For example, given: nodes: {A, B, C, D} with edges: {(A,B), (B,A), (A,C), (C,D),...
3k views

### How to convert vector values to fit k-means algorithm function?

I have a set of user objects that I want to group using a $k$-means function from their quiz answers. Each quiz question had predefined answers with letter values "a", "b", "c", "d". If a user answers ...
13k views

### How to plot/visualize clusters in scikit-learn (sklearn)?

I have done some clustering and I would like to visualize the results. Here is the function I have written to plot my clusters: ...
24k views

### Is it necessary to standardize your data before clustering?

Is it necessary to standardize your data before cluster? In the example from scikit learn about DBSCAN, here they do this in the line: ...
65 views

### Spatial clustering of data points on a grid to obtain variable resolution map with constant statistical confidence

I have a grey valued image which is calculated as the mean of a series of images. The value of each pixel is therefore associated to a standard error. The pixel values and the relative standard error ...
313 views

### R: Comparing dissimilarity between metabolic models with discrete wavelet transformation

Iām working on comparing bacteria metabolic models. Each model has a set of metabolites (around 2000) and their concentration for 200 time points. Iām in the process of comparing the models to cluster ...
17k views

### K-means incoherent behaviour choosing K with Elbow method, BIC, variance explained and silhouette

I'm trying to cluster some vectors with 90 features with K-means. Since this algorithm asks me the number of clusters, I want to validate my choice with some nice math. I expect to have from 8 to 10 ...
3k views

### How to calculate most frequent value combinations

I have the following CSV data: ...
4k views

### How to evaluate clustering success in a completely unsupervised system?

The algorithm in question is Kohonen's SOM. But the question could also apply to PCA and some others. When the umatrix (or the codebook?) is examined, is there a way to tell how successful clustering ...
169 views

### Definition of “inside” in K-means?

After conducting a cluster analysis using K-means, I have new data coming online that I need to detect anomalies with. Anomalies are assumed to not be within the clusters. So, how is one to define "...
87 views

### Spatial clustering based on response to inputs and building a reduced model

Stats version: I have a few measurements of a function that takes three inputs and produces a few 2D fields of outputs: $f_i(a,b,c;x,y)$, with $f$ being a vector of several quantities. I would like to ...
665 views

### How are clusters from DBSCAN sometimes non-convex?

I've been using clustering in my bag of ML techniques for quite some time now, and I've never found a satisfying answer to this question. In DBSCAN, we define a maximum radius with which to form ...
91 views

### Joint spatial clustering: How to force clusters to minimally contain datapoints from all datasets

I want to jointly cluster datapoints coming from different datasets (50 datasets with around 2000 points each). I would like to then extract information associated to the datapoints belonging to the ...
109 views

### Clustering uncertain data with independent uncertainty per dimension

I have $n$ objects located in a $d$ dimensional space, however I do not know their exact coordinates. For each object and each dimension, I have a set of noisy measurements of the coordinate. I would ...
291 views

### Kmeans on mixed dataset with high level for categ

My retail dataset contains 3 numeric attributes and two categorical attributes Time and ID with 50,000 records. Both categorical attributes have more than 20 thousand levels and their format is 1/11/...
171 views

### User profiling with Mahout from categorized user behavior

I'm trying to cluster and classify users with Mahout. At the moment I am at the planning phase, my mind is completely mixed with ideas, and since I'm relatively new to the area I'm stuck at the data ...
273 views

### Can you use clustering to pick out signals in noisy data?

As my first project into data science, I would like to pick out the main clusters in noisy data. I think a good example would be trying to pick out certain links on a given StackExchange question that ...
91 views

### SPSS style custom tables in Orange

Is there a way to draw custom tables like in SPSS where you put some attributes to rows and some to column to visualize clustering results?
1k views

### Algorithm for segmentation of sequence data

I have a large sequence of vectors of length N. I need some unsupervised learning algorithm to divide these vectors into M segments. For example: K-means is not suitable, because it puts similar ...