Questions tagged [linearity]
The linearity tag has no usage guidance.
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Test Linearity Assumption - Hayes PROCESS
Before running the Hayes PROCESS for my moderated mediation, I would like to ensure first, that the linearity assumption is fulfilled.
However, at this point, I am not sure which variables need to be ...
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How to Check Linearity Assumption in Logistic Regression with a Large Dataset?
I am working with a very large dataset that essentially covers the entire population of interest. I want to assess the linearity assumption between an independent variable and the log(odds) of the ...
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Upward trend in Residuals vs. Fitted - Violation of linearity?
I am currently working with longitudinal data using a linear mixed model (lme4 R package).
The linearity plot (fit with ...
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Provide an intuitive example of the linearity of expectation
Can anyone explain the linearity of expectation in an intuitive way? I have been trying to understand this for far too long now. Please don't use any equations and such, try to use real world examples ...
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Challenges with achieving linearity in multiple linear regression analysis
What steps can I take to correct for linearity assumptions in a multiple linear regression analysis conducted in Python on a dataset with 79 independent features, including 22 continuous, 28 nominal, ...
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How to interpret scatterplot to test linearity b/w covariate and DV?
I'm doing an ANCOVA on a fictitious dataset of math test results (DV) by group (n1 = 50 online training; n2 = 50 no training) with previous math ability as a (covariate) to see if there is a ...
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What to do with non-linear environmental correlates in NMDS variance analyses?
This is in response to @GavinSimpson's answer to NMDS and variance explained by vector fitting.
From this post, Gavin shares the following:
...the vector fitting approach is inherently linear and we ...
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213
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Continuous predictor variable has non-linear association with log odds of response
I'd like to know if a continuous predictor variable (sal) predicts a binary response (empty) in a logistic mixed effect model, but discovered there is a non-linear relationship between the predictor ...
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Test For Linearity, what happens when the sig value for Deviation From Linearity is 0.05? [duplicate]
I Log transformed a variable to make it more linear and ended up with a 0.05 in Deviation From Linearity. What does this mean? I know that >0.05 would indicate linearity but what about this case?
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355
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Testing the linearity assumptions for categorical predictors
Me and my friend are currently writing our final essay but we are having some problems with our analysis…
We are doing an hierarchical multiple regression, and we has some categorical predictors (like ...
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Transforming (non-significant) covariates in stratified logistic regression
I am running several stratified logistic regression models. My three key predictors are all significant and linear (with the logit of the outcome). Four covariates (continuous) are mostly ...
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242
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Interpreting QQ plot
Can we say that the assumption for linearity is met? I'm confused because the tails are heavy, and deviations have a bow-shaped pattern. Still, I think that the linearity has met because the majority ...
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How to interpret Box-Tidwell p-values when sample size is large?
I have a dataset of 300 independent variables and 120,000 observations for which I will perform a binary logistic regression on my dependent variable. Because of the linearity assumption between the ...
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Is this relationship between variables linear?
I have four research questions and all of them has the same main "independent variable", as such the relationship between x and y1, y2, y3, y4. This is not a multivariate analysis, I am just ...
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126
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Linear regression has good performance in validation set despite not meeting the linearity assumption
I have a dataset with about 8000 samples and 18 predictors (16 continuous, 2 categorical). I am trying fit a linear regression, but despite trying multiple transformations, I can't make it meet the ...
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Correlation = 1 with three random variables
Let $A, B, C$ be random variables with covariance $cov(A B) = 0$ and correlation $corr(B, C) = 1$.
Is it true that $cov(A C) = 0$?
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Prove linearity of impulse response model
Given the following time varying model:
$Z(t) = \alpha*t*Z(t-1)$,
how do I go about proving linearity? If you simplify based on some constant at Z(0), you get the general solution $ Z(t) = \alpha^tt!Z(...
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OLS linearity assumptions
Do we have to check on stata that the OLS assumptions of linearity of a regression if the regression is already linear in parameters? I'm having trouble with this concept.
Thanks in advance.
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Why doesn't a residual plot indicate whether or not the linearity assumption is violated?
I learned in stats that a residual plot is a plot of the residuals on the vertical axis and the independent variable on the horizontal axis. So basically it looks like the regression line turned ...
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Exploring relation between x and y [duplicate]
While there are numerous methods in exploring relation between x and y upon receiving a new dataset. Yet it seems I can't find any conclusive guide as of the sequence of analysis, e.g. do correlation ...
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How to decide the best form of BMI used in cox regression, categorical or continuous?
BMI is always analysed in the form of a categorical variable in medical research. In my Cox regression model, I kept BMI in its original form, i.e., a continuous variable. But the reviewer asked how I ...
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Assumptions of linearity and homoskedasticity when the DV is a Likert scale - how to interpret the (optimized) residual plots?
I am currently building mixed models for several analyses where each the DV is ordinal, specifically a 7-point Likert scale. Now, I am fully aware of the controversies of using Likert scale as a DV ...
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Can someone clarify what the linear assumption of PCA is?
For the past few hours I've been trying to search what this linear assumption is. Some of the articles states that that your independent variables have to be linear in relationship and need some type ...
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An Unexpected Expectation!
Due to the linearity property of the expectations, we can write $E(X+Y) = E(X)+E(Y)$. But in Chapter 6.1 of the book, "Counterexamples in probability", the writer, Jordan Stoyanov argued ...
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linearity in parameter assumption - implication for the Gauss-Markov theorem [closed]
Even if a similar question has been asked many times, I have not been able to understand the consequences of non linearity in parameter in relation to the Gauss-Markov theorem.
In this question ...
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189
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Difference between Dickey-Fuller test and testing for linearity
The Dickey-Fuller test tests an AR(1) series for stationarity.
An AR(1) series can be written as:
$x_t = \phi x_{t-1} + \epsilon_t $
with $\phi$ constant and $\epsilon_t $ white noise.
The series is ...
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401
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Box-Tidwell of same variable in two different logistic models
I'm running two identical logistic models on two different (and with mutually exclusive 1's) DVs on the same dataset. I have an independent variable with similar coefficient in both models and I ...
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Assumption of linearity between variables and log odds in logistic regression
I know that in logistic regression we assume a linear relationship between the independent variables and the logits.
Can you explain why is this a reasonable assumption?
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Solution in case of violation of the linearity assumption in the logistic regression model? (possibly in R)
I have a problem with my logistic regression that I set up and I hope someone can help me.
(I am working with R)
My data is based on hourly values. The dependent variable is a dichotomous variable (1 ...
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Valid alternative to Box Tidwell method for Linear Regression [duplicate]
I am building a Logistic Regression model (in sklearn) and want to verify that the assumption regarding the linearity between X and the logit function is correct.
I am using Python so am looking for ...
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How to test linearity in ordinal logistic regression analysis?
One of the assumptions for performing ordinal regression is linearity. How to test this for this specific type of regression? Do you have to use logit etc.? And how does this work in SPSS?
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Does this scatter plot suggest non-linearity?
As part of assumption testing for ordinary least squares (OLS), I am examining the linearity between the variables in my model. I'm using scatterplots between the independent variables (IVs) and ...
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Relationship between Histogram , Scatter plot , Normality , Linearity
I have the following doubt: suppose you have a categorical variable called 'neighborhood' with 20 categorical levels/values ("vila madalena", "mooca", etc). and I want to check ...
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Multivariate normal distribution property [duplicate]
The Econonometrics book by Hansen mentions this property of a multivariate normal distribution:
If $X∼N(\mu,\Sigma)$ then $AX+b∼N(Aμ+b,AΣA^\prime)$. It goes to say that a simple implication of this ...
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Assumption logistic regression: linearity of independent variables and log odds?
I checked whether in my logistic regression models the assumption of linearity between the independent variables and the log odds is met. I used R and followed the instructions on this website to do ...
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How to Assess Linearity assumption of logit in logistic regression
In Applied Lineare Regression, (Hosmer, Lemeshow, Sturdivant 3rd ed.) Ch. 4, they present "Purposeful Selection." Part of step 5 is to assess the validity of the linearity assumption of the logit vs ...
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Dealing with violation of OLS assumptions
I am currently writing my Master's thesis in economics. I am analyzing the second home rate in Swiss municipalities in R.
The second home rate for municipality $j$ is defined as the share of the ...
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Mixed Model in R: Test for linearity and inclusion of lagged variable
I have specified a mixed model in R, based on a data set containing advertising awareness as DV and advertising spends as IV. The effect of the advertising spends on awareness is moderated by two ...
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Prove or disprove the Linearity of Expectiles used in Expectile Regression
For expectation (mean), there are many useful properties such as Linearity of Expectation:
$\mathbb{E}[X+Y]=\mathbb{E}[X]+\mathbb{E}[Y]$
$\mathbb{E}[\alpha X]=\alpha\mathbb{E}[X]$
(The 2 equations ...
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linearity of a measurement device
I like to evaluate the linearity of a measurement system. In order to do so I read ISO 22514-7 as well as Breyfogle's "Implementing six sigma". However, the procedure is still unclear to me. So I'm ...
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Why is linearity (as in linearity in BLUE) a desirable property for OLS estimators?
By linearity, I do not mean the linearity of the estimators in the OLS regression equation, what I am trying to ask is why are the beta coefficients a linear function of y(i)'s. Why is linearity a ...
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Linearity assumption of logistic regression [duplicate]
Do I have to check linearity assumption of logistic regression
(Log odds of outcome with continuous variable)
using graph of predicted logodds (by logistic regression) and continuous variable
Or
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Is there a way to differentiate between linear and non-linear datasets in simulations studies?
I'm trying to find a a measure of "linearity" among different simulated data sets and how I could control for such differences.
This idea came from studying Hastie's and Tibshirani's work around ...
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Should one drop independent variables if they don't have linear relationship with the response variable?
I am building a linear regression model using Ridge regression. Some of the independent variables don't have linear relationships with the dependent variable. I've tried to do data transformations on ...
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Linear regression, linearity assumption violated?
Below i have attached a scatter plot showing my dependent variable on the Y-axis and my independent variable on the X-axis
I am not sure if the linearity assumption is violated? Can anyone explain ...
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SEM 4 questions - testing linearity, sum score, number of variables, independent variables
For my master thesis I'm making a structural equation model.
However, I do not have much experience with this. So here are some different questions.
I read that one of the assumptions important for ...
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How to check the linearity of continuous variable in linear mixed model
I'm doing a linear mixed model using lme.
In my adjustement factors, I have a continuous varaible (named X1). And I want to check the linearity of this variable using a spline function or a ...
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317
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Model assumption of linearity
I am trying to interpret the outcome of a test for assumption of linearity. This is the dataframe:
...
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Is checking for normality and linearity in this way correct?
Testing normality using a significance test is a little bit useless especially when you have a large sample size
So, recently I found a way to test normality by running a fake regression using ...