# Tagged Questions

Measure of distance between distributions or variables, such as Euclidean distance between points in n-space.

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### Comparing the degree of similarity between groups

I have three groups A, B and C and I want to prove that similarity between group B and group A is significantly higher than between group B and group C. How to prove it? Simple example: I have ...
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### Mahalanobis vs Bhattacharayya distance

I am currently trying to study class separability in a binary classification problem. I found Bhattacharayya distance to be a good (and canonical) separability measure, but it appears that Mahalanobis ...
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### Does vector normalization alter distance relationships?

Simple question, but one I'm struggling to visualize. Does L2 normalization affect the Euclidean distance computation between pairs of vectors? I can't imagine it would, because it's just the length ...
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### Distance Metrics for Comparing Theoretical Sampling Distributions

I have a sampling probability density function (denoted $f(x|M,N)$ that becomes hard to calculate for large degrees of freedom (i.e. as $M$ and $N$ get big). If I have another pdf (say $f^{*}(x|M,N)$ ...
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### Any distance measures that are more useful for binary data clustering?

I was taking a look at Clustering a binary matrix but it didn't seem to answer my question. I used a basic euclidean distance measure which definitely works but I am exploring alternative distance ...
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### how to find similarity based on only one column value

I am not sure if it is possible and that is why I am asking the question here. I have a data looks like below ...
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### How badly does it affect if we compare two machine learning algorithms one using Cosine Sim and other using Cosine Distance?

I am working on a research project such that I need to compare several distance based classifiers - say TF-IDF based KNN and Kmeans for clustering. Suppose I use Cosine Similarity for one and Cosine ...
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### Mahalanobis Function with test and train data

I am new to R programming. I was given a task at work with minimal explaination. I have a huge Data set. Can someone explain the use of Test data and train data? How to use that along with a ...
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### Permanova for microbial ecology using adonis (R): should I include block?

I know this is a very basic question, but I have been quite unsuccessful in finding a good solution to the following issue. First the data. My spreadsheet is too big, so here is a fictional example: ...
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### Cosine distance between two vectors containing positive as well as negative elements

I have two vectors whose elements $\in \mathbb{R}$. Everywhere I have seen the usual definition of cosine similarity and the distance = 1 - similarity. However, on ...
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### estimate NND in the cluster with missing data [closed]

Would very appreciate any comments on the following problem: Imagine one has N sets of elements (points on the plane), coordinates (x,y) of 30% of the points in each set are known. So if we have 30 ...
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### Euclidean distance between the unbiased covariance estimator and the true covariance

Let X be a n*p matrix whose p columns are sampled from a centred normal multivariate distribution with true covariance matrix $\Sigma$ and let $\Sigma_{n}$ be its unbiased sample covariance estimator ...
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### Does it make sense to cluster based on Euclidean distances between rows of a cosine matrix?

I calculated the Cosine distances for binary data and got the relations between different variables. I need to cluster them. I tried passing the cosine matrix directly to the (clustering) function ...
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### How to calculate the distance in KNN for mixed data types?

when the data is from different types (numerical and categorical) of course euclidean distance alone or hamming distance alone can't help. so i have 2 approaches: standardize all the data with ...
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### How Gower's dissimilarity handle missing values in numeric columns?

I would like to ask a question about Gower dissimilarity, I was wondering how Gower measure handle missing values in numeric columns, especially that Gower standardized each column based on the range ...
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### How to deal with non-independent data when comparing populations across a range of distances

I am trying to figure out how to carry out an analysis but am having trouble finding any information. I am interested in finding out whether values of sensitivity across populations are more similar ...
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### Kolmogorov-Smirnov test between two distributions - R

I've two distributions computed on the same grid (that is, for each point of the grid I know the value of each CDF at that point). I want to check whether the two distributions are the same. I can't ...
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### Distance Estimation from Signal Level?

So, I want to learn about machine learning and apply it to my project. I have set of data which includes position of a car and unknown emitter signal level. I have to estimate the distance based on ...
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### Metric from a positive definite matrix

I'm trying to prove that the Mahalanobis distance is an actual distance, more in general Given B symmetric and positive definite matrix set d(x,y)=(x-y)'B(x-y) ( ...