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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Testing for MCAR in univariate time-series

I have a large dataset consisting of hourly energy measurements over a period of 2 years for 1500 buildings. Since the energy consumption of one building can be assumed to be independent of the ...
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how to interpret the contribution of a variable, when univariate vs multivariate analysis result differs (survival analysis) [duplicate]

Not well versed in statistics so I do not know if my question is limited to survival analysis or has a general solution to similar types of questions. I saw a clinical trial study demonstrating that ...
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43 views

Copula between a distribution and its univariate transformation

I'm trying to compute the copula (or joint distribution) between x and a univariate transformation, like say sin(x). That is compute $C_{XY}$ (or $F_{XY}$) given that $x \sim U(0,1)$ and $y = sin(x)$ ...
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30 views

Selection of variables based on clinical knowledge in multiple logistic regression

Dear Cross Validated community, I am conducting a multiple logistic regression for a case-control study. There are too many predictors to be investigated. My question is "Can I choose which ...
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12 views

How to represent dependencies between horizons and uncertainty when forecasting multiple horizons?

Suppose the following case of univariate time series forecasting. We forecast sales of a product 1 till 7 days ahead. The true distribution of the actual sales is the following: there is a 100% chance ...
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54 views

Question regarding selection variables for a multiple logistic regression analysis, through univariate analysis

I use univariate analysis to select variables for a multiple logistic regression. However, one of the categorical independent variables has a non significant dummy (one of the three). Should I include ...
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177 views

Does this distribution have a name? $p(x) \propto |x|^a \exp\left(-\frac{1}{2} (x-b)^2 \right)$

Quick question. Anyone able to attribute the following kernel to a known probability distribution (univariate, continous on the real line)? $$ p(x) \propto |x|^a \exp\left(-\frac{1}{2} (x-b)^2 \...
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40 views

forecasting with optimised theta method (otm) using time series cross validation with R

I want to do an out-of-sample forecast experiment using the optimised theta method (otm) on a time series. Further, time series cross validation with a fixed rolling window size should be applied. ...
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No significance in the multivariate tests

Hope this question is not too stupid. I haven't taken the MANOVA course yet, but I need to figure out a problem right now. I am running a mix-model MANCOVA on SPSS. I have no significance in the ...
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29 views

Univariate Competing Risk Analysis with R

I need to carry out a competing risk analysis, and I am using this paper as a guide. The first question: the exp(coef) is the hazard ratio? The second: how could I carry a univariate analysis (I need ...
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32 views

Generating samples from a histogram

I don't quite know how to ask this question or what to search for but I'm certain this method has a name.. I have a uni variate binned distribution, something like x = { 0, 10 , 20 , 30,....} with ...
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1answer
31 views

Chi squared test assumptions not met

I want to perform a univariate analysis to predict if a higher BMI is associated with an increased incidence of complications after surgery. I divided the BMI of patients in 4 categories (<18.5; 18....
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Multiple linear Autoregression

i'm new at statistics and can't be sure with my equation, which model it is. I have a dependent variable Y (from 1.Jan. 2020 to 20.March., every 10 seconds.) and independent variables in the same ...
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1answer
33 views

What is the best way to model such time series?

I have this time series where a peak occurs every around 5 years and the structure changes after each peak. What do you think is the best way to model such time series? Can this be modeled using the ...
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78 views

Statistical analysis of amino acid profiles, quantitative vs qualitative methods?

I work on a study comparing the amino acid profile of 5 sample groups with 3 replicates in each group. This is how the data looks like except that there are 17 columns (one for each amino acid) in ...
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946 views

How to set (p,d,q) and (P,D,Q) for SARIMA time series model

I have a time series dataset of monthly average temperature in Cayman from year 1823 to 2013, with dickey-fuller test = 0.008275 (I assume the series to be stationary since the test doesn't exceed 0....
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The utter futility of bivariate analysis

Consider the following quote from here: Moreover, univariable prefiltering, sometimes also referred to as “bivariable analysis,” does not add stability to the selection process as it is based ...
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1answer
79 views

Uni-variate hourly time series anomaly detection by TBATS

I have hourly and +4 years length of air pollution data (PM10). It has 24 (daily), 168 (weekly) and 8766 (yearly) seasonality. Also distribution is right skewed and has very long tail. I want to make ...
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30 views

The sufficiency of univariate selection

Why is feature selection such a common topic, when one could simply use SelectKBest to find the optimal set of features? The only trouble would be to find the best ...
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1answer
2k views

How to plot cost function against iterations? [closed]

I am new to coding in machine learning. I am trying to plot a graph for the gradient descent of a univariate function. ...
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203 views

Univariate vs multivariate analysis (p-value)

So I have been looking through some literature/articles, and something I often come across is, that when they do some kind of analysis it's often univariate and multivariate analysis on for example ...
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154 views

In a linear regression hypothesis equation, what does each symbol represent?

So I've been watching Andrew Ng's machine learning lectures, and I'm on a video about univariate linear regression. He was talking about how a Hypothesis takes an input and predicts an output, like a ...
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2answers
61 views

Estimating parameters for the product of a lognormal random variable and a uniform r.v

Suppose I have a random variable which I suspect is the product of a lognormally distributed random variable $X$ and an independent uniformly distributed variable $U(0, 1)$. (The variables are the ...
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369 views

LSTM model for multistep univariate Time series forecasting

I have scenario where i have time series data (1 per day) for past 365 days. And I need to make a prediction for next 365 days. Is this possible using LSTM or any other ML models. I have been through ...
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38 views

Logistic regression interpretation in SPSS statistics

I observed a very strange behavior while doing logistic regression, univariance analysis and correlation analysis. I have dependent binary variable and several independent variables that should be ...
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188 views

Claims and questions regarding $n$-ball distribution?

CONTEXT In my research, I am utilizing an $n$-ball 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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794 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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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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30 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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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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2answers
155 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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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
58 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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38 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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2answers
46 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
31 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
19 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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1k 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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21 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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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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58 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
59 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
141 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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901 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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34 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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444 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
80 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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39 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

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....