1k views

A better Outlier Detection approach! [duplicate]

Currently I am using Cook's distance to detect outliers in multivariate data. Is there any better approach than Cook's distance for the same?
967 views

How to detect outliers? [duplicate]

I have a matrix where the rows are the data points (samples) and the columns are the features (predictors). Let's say I have 1000 data points and 20 features, i.e. the matrix is of size 1000 x 20. ...
639 views

Detect outliers in multi dimensions [duplicate]

I tried to implement outlier detection for one dimension using inter quartile. For instance, a given variable cost or revenue or profit. but I'm missing outliers in other dimensions when running for ...
153 views

What are the methods for multivariate outlier detection? [duplicate]

I have to work with research paper using multivariate outlier detection methods. Please list the methods for multivariate outlier detection and give some suggestions and ideas....
36 views

Outlier detection in high dimensional data [duplicate]

I am looking to clean up a large data set (~300) with a large number of features (~140). I would like to explore outliers in the data. My first thought was to use PCA to reduce these features to a ...
10k views

Rigorous definition of an outlier?

People often talk about dealing with outliers in statistics. The thing that bothers me about this is that, as far as I can tell, the definition of an outlier is completely subjective. For example, ...
29k views

Is there a simple way of detecting outliers?

I am wondering if there is a simple way of detecting outliers. For one of my projects, which was basically a correlation between the number of times respondents participate in physical activity in a ...
5k views

What are the multidimensional versions of median [duplicate]

What are the multidimensional versions of the median and what are their pros and cons? I confess this doesn't have a single answer, but I think it is a useful question to ask and will be a benefit to ...
3k views

Finding the average GPS point

I need to write a program to find the average GPS point from a population of points. In practice the following happens: Each month a person records a GPS point of the same static asset. Because of ...
7k views

Anomaly detection: what algorithm to use?

Context: I'm developing a system that analyzes clinical data to filter out implausible data that might be typos. What I did so far: To quantify the plausibility, my attempt so far was to normalize ...
5k views

How to find quantiles for multivariate data using R?

Quantile for a single variable is easy to implement in R. However, it is not an easy task to quantile for multivariate data. There are several papers have been proposed to quantile for multivariate ...
2k views

Identifying outlier data in high-dimensional settings

I have a data set with high-dimensional feature space. Are there any pre-processing methodologies that can detect outliers from this data set? The outlier, I mean, are the ones that tend to be very ...
1k views

Does Pearson correlation require removal of bivariate or univariate outliers?

Does the Pearson's correlation estimator require no bivariate outliers, or no outliers in each of two individual vectors of data? The answer will impact on how I winsorize outliers before calculating ...
I have been given a set of data points $(x_i,y_i)$. I have to plot a scatter plot and determine if there are any outliers. But I haven't been taught a method to measure which data point is an outlier ...