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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zero-lag filter: size of negative part of filter weights: when in-phase with sinusoid?

This question is about negative weights in causal filters and their effect on the lag, or "synchronization" with a sinusoidal signal. There are a few types of moving averages that use negative ...
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25 views

Claims and questions regarding $n$-sphere distribution?

CONTEXT In my research, I am utilizing an $n$-sphere distributions along with two related distributions. I'd like to make certain I have a firm handle on the way to describe my three distributions. I ...
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53 views

Is the chi square test one type of univariate analysis?

Somewhere I read that for categorical variables, the univariate analysis includes only descriptive information. What about chi square test? Could not we assume the chi square test as univariate ...
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Is there a standard name for this continuous distribution? [closed]

I'm encountering the following PDF of continuous scalar real $X$ with semi-infinite support $]0,+\infty[$: $$ f_X(x) = C ~ x^{-\alpha} ~_1F_1\left ( a,b;-\frac{d}{x^\beta} \right ),~~~~~~\beta>0;~\...
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25 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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51 views

Comparing univariate and bivariate models [closed]

I have a bivariate dataset, that is, $(\boldsymbol{y}_i, \boldsymbol{x}_i)$ for $i = 1, \ldots, n$, where $\boldsymbol{y}_i = (y_{i1}, y_{i2})$ and $\boldsymbol{x}_i = x_{i1}, \ldots, x_{ip}$ are ...
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103 views

How different will that be between the R-squared of linear regression y~x and square of cor(x,y)

Generally, both of them can represent the linear relationship between x and y scale to [0,1]. Are they 99% very similar?
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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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1answer
49 views

Verifying Identification Results for Univariate Regression

So I have this linear regression model shown below and I'm supposed to be showing that equation 3 is equal to equation 4. There's a hint that says a 2x2 inverse matrix appears in the proof, but the ...
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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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20 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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44 views

Which test you recommend?

Assume in a study the dependent variable is quantitative, while most independent variables are categorical, with some of them being quantitative. We aim to evaluate the relationship between the ...
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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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1answer
18 views

Which command should be used in SPSS for calculating p value without confounding factors effect?

In a study, we have the disease as dependent variable ( 0 or 1 patient or healthy); some independent variables are real and some of them are confounding (some of varibles are quantitative and some of ...
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2answers
338 views

p-value for univariate analysis

So I am reading an article in which it has a table showing p-values and hazard ratios for what they say is "Univariate and multivariate analyses of clinical and treatment factors potentially ...
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18 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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395 views

What is the point of univariate regression before multivariate regression?

I am currently working on a problem in which we have a small dataset and are interested in the causality effect of a treatment on the outcome. My advisor has instructed me to perform a univariate ...
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48 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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45 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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56 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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445 views

Different p-values for coefficients and LRT in univariate cox regression (coxph R)

I have used Cox PH to test the relationship between one predictor and survival for 6 patients. Cox PH was used since the predictor is continuous. Using the "cox.zph" function, there was no significant ...
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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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217 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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1answer
64 views

Univariate regression analysis - unexpected sign

I am performing an univariate regression analysis by basically regressing a default rate on macro economic variables such as $DR = \alpha + \beta GDP$ I noticed that sometimes the sign of the betas ...
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25 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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128 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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74 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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341 views

Derive Spearman correlation (rather than Pearson's) coefficient from a univariate regression?

In univariate regression, the standardized coefficient is equal to the Pearson correlation coefficient. When the two variables are ranked variables, Spearman correlation would be appropriate. Is it ...
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1answer
356 views

How to adjust for a temporary 12-month level shift in time series?

I am working with a time series on monthly base (April 2004 - Oct 2016) in order to identify an ARIMA model and do forecasting. This is the time series I examine: month;volume Apr 04;2.555 Mai 04;2....
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403 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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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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434 views

Express multivariate normal as a univariate normals

I want to find the univariate normals of a multivariate normal in order to plot them. If we assume that each are independent, then I know that we can use the mean vector and diagonal of the covariance ...
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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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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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54 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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195 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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3answers
2k views

Alternatives to Using ARIMA for forecasting

I've been dealing with mostly univariate time series data and am wondering what alternative models exist for forecasting instead of ARIMA, ARMA, AR and MA processes, I know about exponential ...
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47 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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1answer
345 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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1answer
622 views

Are the marginals of the multivariate t distribution univariate Student t distributions?

Are the marginals of the Multivariate t distribution with $\nu$ degrees of freedom univariate Student t distributions with $\nu$ degrees of freedom?
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42 views

For univariate outlier analysis should I use z score if my data is skewed? [duplicate]

If my data is skewed, does it mean that my data does not follow a normal distribution? How do we define various distributions? What type of outlier analysis do I perform for the different type of ...
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180 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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1answer
47 views

Comparing effect sizes across univariate regressions with identical independent variable but different dependent variables

I have done several univariate regressions with investor sentiment as independent variable (identical across regressions) and different sector portfolio returns as dependent variable. Can I infer ...
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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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2answers
46 views

Generates variates of $F^s$ given a known algorithm for variates of $F$

Let rv $X$ have a distribution $F (t):={\rm Prob}(X <t)$ and rv $Y$ have a distribution $G (t):=(F(t))^s$ for some constant $s>0$. Suppose that I know an algorithm for generating random variates ...
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261 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 ...