Questions tagged [univariate]

Pertaining to a single variable. Univariate statistics deal with only one variable - e.g. the mean, standard deviation, range etc. Univariate distributions involve only one variable e.g. the univariate normal, uniform etc. distributions.

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131 views

Graphical summaries of relationships between univariate distributions

I'd like to review published papers or book chapters (so I could formally refer to them) that graphically illustrate the parametric relationships between univariate distribution families. The papers ...
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23 views

Definition of stable distribution

In some places, I find the following definition of stable distribution: A distribution is said to be stable if a linear combination of two independent random variables with this distribution has ...
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396 views

Univariate and multivariate outlier detection

I have a dataset with several features (about 15), and I am interested in finding outliers. My approach is to perform univariate analysis to highlight outliers in the single features and multivariate ...
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1answer
57 views

Seek tool for univariate exploratory analysis

Looking for a tool to assist with univariate exploratory analysis as an early step in a model building process. Capabilities I’m looking for are to recode or transform the raw predictor variable, x, ...
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29 views

Which statistical test to use in R? Unbalanced design with one dependent variable and multiple independent variables

it's been a while since I've had to do any statistics and I need a little help determining which statistical model/test to use in R. My background is more with multivariate stats, so it's been a while ...
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191 views

Filter methods for feature selection are often univariate. What multivariate filter methods exist, and what are their dis/advantages?

Feature selection approaches are often grouped into three categories: "filter", "wrapper" and "embedded" approaches. Filter methods tend to assess the inclusion of an attribute based on some scoring ...
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68 views

Interpreting results of mvnorm.etest using energy package in R

I need to use functionalities of the energy package installed in R to give energy test of normality. So, as given in its documentation here https://cran.r-project....
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9 views

Index creation for studying “average” time series properties

I have 300+ financial time series from an "unknown" asset class. To study the dynamic properties of class my idea was to collect them under an "index" and then study it as an univariate time series. ...
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38 views

Is it mathematically correct to re-analyse data as ordinal after having analysed as continuous using the same rank based method (nparLD)?

Please tell me why I'm wrong :) I have a dataset collected in a 2 by 4 repeated measures design, where 2 separate groups of people were tested 4 times on the same task. I have analysed my data with ...
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53 views

Statistical significance vs.classification accuracy

Apologies if this question has been asked before, but I could not find very relevant topics. I am working with proteomic data (40 proteins, 800 instances) where the outcome variable is binary (...
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1answer
344 views

Univariate ANOVA: how to deal with independent variables that are subsets (SPSS)?

I have speech recordings which have been assigned opinion scores (1-5). These recordings were performed by 10 speakers, 5 male and 5 female. I want to investigate the influence of both the specific ...
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178 views

Difference between multiple regression with categorical independent variables versus numerous univariate regressions?

I have a dataset about the functionality of rural water supply points (boreholes etc) and I am undertaking a logit regression. My independent variables of interest are the type of water point (about 5 ...
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2k views

Imputation in monthly univariate time series

I have a time series of the amount of apples sold in a specific Region. The time series include monthly values of 10 years (2006-2016). However two months are missing (February 2009 and July 2014). ...
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37 views

Do I run a 3-Way ANOVA on SPSS if one of my IV is just there to form a control group?

I'm trying to see what effect different doses of a drug (IV 1) have on the behavior (my dependent variable) of a rodent model; specifically, whether there is a significant change in this behavior ...
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146 views

How to compare three univariate time-series?

I'm new at the StackExchange but got a lot of useful info by reading the posts in the past. Now I'm struggling to find the best way to statistically address my research question and would love to get ...
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1k views

Change point detection with Matlab

I'd like to detect changes in mean in time series data. I've been using R successfully with the ecp (cp3o) and BreakoutDetection libraries. I need to transfer my code from R to Matlab and are therefor ...
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271 views

Eta square and effect size in General Linear Model

I have an unbalanced data set that is categorized in 3 different topics. I wanted to see that how these different topics are effecting the data. So I used ...
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127 views

What type of model should I use? (Time series, univariate, dependent variable is a count)

I have a univariate model in which I am looking to predict the number of articles per week in a newspaper about a protest (count data) by how many arrests of protesters occurred per week. I have 148 ...
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1answer
103 views

Comparing treatment means with lots of zeros

I am trying to compare the means of two treatments on a continuous variable with a lot of zeros in it. I've tried a log(n+1) transformation but that did not get me to a normal distribution. Any ...
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447 views

Trend and seasonality tests for a univariate time series

I am working with a batch of about 1000 univariate time series in R . For every time series, I have to perform following tasks , before deciding upon a model be it ARIMA, TAR or Holt Winter's Model ...
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383 views

General linear hypothesis testing in repeated-measures multivariate linear model

In a multivariate linear model $Y = XB + U$, where within-subject (or repeated-measures) factors are coded as simultaneous response variables in $Y$, a general linear hypothesis can be formulated as ...
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24 views

Correlation between univariate time series

I'm wondering about what preprocessing steps are common before taking correlation between univariate time series. I usually normalize the data, but I'm also wondering if the spacing is important as ...
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26 views

Is it possible to do forecasts using regression algorithms and only 2 variables?

I have a dataset with 2 variables: "_time" and "logins". I trained a model with the month of MAY. Then I applied that saved model on the month of JUNE (this is unseen). Is it possible to use a ...
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17 views

Creating multivariate regression model out of multiple univariate models

A bunch of ML regression models are defined only for predicting the value of a single variable. Or have standard implementation that are only for the univariate case. For example support vector ...
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9 views

Appropriate analysis for univariate proportion data and environmental variables

I'm new to statistics so am trying to choose the best analysis to find if; There is a difference between canopy cover (0-100%) at different sites There is a relationship between canopy cover and ...
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19 views

Generalized logistic distribution

I saw on wikipedia https://en.wikipedia.org/wiki/Generalized_logistic_distribution that when $\alpha<\beta$, generalized type IV logistic distribution can be written as: $\frac{\exp(-\alpha x)}{(\...
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1answer
30 views

what is alternative/opposite to piecemeal statistical approach?

I have only basic knowledge about bio-statistics. For not normally distributed data, I used Kruskal-Wallis test to investigate the statistical significance between different variables. I performed an ...
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17 views

Univariate time series for multiple devices

I have about 50k devices, which either fail (0) or connect (1). I have data for the past 300 days for all of them. I'm trying to predict when a device will next fail. The devices are all more or less ...
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47 views

Univariate Feature Selection KBest Test Score Function with Binary Target

What is/are good score functions for univariate feature selection tests when the target variable is binary? Are any of the available scoring functions bad, aside for the regression functions of course....
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44 views

multi-response outcome: multivariate or univariate regression?

I have a dependent variable which represents participants' responses on 20 words, coded as 1 = correct , 0 = incorrect Question: I am keeping the regression as univariate for now (as far as dependent ...
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1answer
47 views

Concept of square in multivariate statistics

This might be more of a linear algebra question, but here we go. I have always been confused about how the concept of squares in $\mathbb{R}^1$ sometimes corresponds to a matrix product $A^{T}A$ and ...
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1answer
46 views

How can I implement univariate Nadaraya-Watson regression for prediction?

How can I implement univariate Nadaraya-Watson regression for prediction? And what is the $x ,x_i$, and $y_i$? How can I select the $x ,x_i$, and $y_i$? The sample for prediction and the shape of ...
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118 views

Box-Cox Transformation on Single Variable and Interpretation of the Transformed Variable's Mean and Standard Deviation

I'm revisiting the Box-Cox transformation in one of my stats books, and I started playing around with the SAS macro %BCTRANS2 (Source: http://support.sas.com/resources/papers/proceedings12/430-2012....
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47 views

Can we use a univariate regression as a dimensionality reduction method?

Assume we have 500 predictors and one response. Can we perform a univariate regression on each pair Y-X and then select the predictors that have the highest R-squared and p<0.05? After that, we can ...
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53 views

What is a qq plot? Is it possible to make a qq plot between age (ranging from 20 to 70) and salary (ranging from 5000 to 10000)?

What I have understood is that it is a graphical technique used to check if 2 data sources (even if not from the same population) have similar data distribution. In that case the scatter plot will be ...
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188 views

Choosing a model based on ACF and PACF vs information Criterion

I'm currently doing some univariate forecasting using a small data set of about 36 observations and R software for analysis. I've found that the basic visual inspection of ACFs and PACFs coupled ...
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46 views

sampler for univariate random variable

I have a univariate random variable $x$ whose density has the following form $$p(x)\propto \int f(x,y,z) \,\mathrm{d}y \, \mathrm{d}z.$$ And the support for $x$ is bounded, let's say $-1< x < ...
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70 views

Run one univariate Analysis or separate One-way Anova's?

I am looking at the effect of delivery of feedback, type of feedback and timing of feedback on job performance. A univariate analysis gives me different significant readings for each variable than ...
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17 views

Derive sequencing probabilities from univariate data

Given a variable measured sequentially e.g. -6,-3,0,2,-3,1,-5,7,-47.. etc, what are some methods to derive some reliable sequencing probabilities? e.g. if i-2>0 and i-1 >0 then i>0 etc.
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256 views

Detect seasonality/ periodicity of a univariate time series with consecutive zeroes

I am working on a time series problem with a single variable which has consecutive zeroes at different periods. The TS plot looks like this: Upon closer examination, the variable has consecutive ...
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86 views

What are other (standard?) distributions that well fit a beta distribution with parameters 3.1 and 1.9?

I have a collection of (200) points that are well-fitted by a (negatively-skewed) beta distribution with parameters $\alpha=3.1$ and $\beta= 1.9$. This is all fine and good, of course, but I am ...
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210 views

Univariate tests of a multivariate model (MANCOVA)

When running multivariate analysis with covariance, the multivariate tests showed all covariates not to be significant, but the grouping variable was significant. When moving onto univariate tests (...
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60 views

Transforming Series with 2nd Moment Nonstationarity

I am trying to induce stationarity in this series. I have graphed a range-mean plot to detect 1st and 2nd moment nonstationarity. Can anyone suggest a transformation that will remedy the 2nd moment ...