Questions tagged [log-linear]
The log-linear model is a form of Poisson regression that allows for the analysis of multi-way contingency tables.
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Appropriate way to visualize significance in 2x3 contingency table using mosaic plot
I've checked multiple threads about handling or visualizing contingency tables, but can't find one that can help my current question. I have a 2x3 contingency table: "group" variable has 3 levels not ...
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18 views
Interpreting log-linear model for contingency table in R
I'm looking at sample data and trying to determine whether there is any association between the height of the husband and that of the wife below. I don't fully understand what the symbolic ...
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12 views
Difference between null and saturated log-linear models
I have data from an experiment testing the number of 'cases' at each of three measurement points (0, 12, and 24 weeks). I am interested in whether the proportion of cases across these measurement ...
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28 views
Interpretation of a log-level regression in its associated 'level' form
Is it conventional to interpret a least-squares regression with a log-transformed dependent variable (log-linear model) in its "level" form? In other words, running a model with the outcome in 'log ...
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19 views
Parameters, constraints and MLE of log-linear models
I want to use log-linear models to assess the type of (in)dependence between variables in $2\times2$ and $2\times2\times2$ contingency tables. In the process of doing so I would also like to ...
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1answer
48 views
Log-linear difference-in-differences
I am estimating several linear models using a difference-in-differences (DiD) framework. The model interacts a treatment indicator (i.e., 1 for the treatment group, 0 for the control group) and a "...
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16 views
When to use a multicategory logit model versus a loglinear model?
Do you only use the baseline-category logit model when categorical responses have more than 2 categories?
How is this different than the loglinear model, which is useful when at least 2 variables in ...
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9 views
Log-Linear Output Help
I ran a loglinear model with 3 variables. Internet Use (Y/N), Nervous Breakdown(Y/N), and Happiness (3 levels). I understand by two way interactions are significant, but I am getting lost trying to ...
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1answer
18 views
logliner analysis on SPSS with more than 10 variables
I want to run logliner analysis on SPSS Statistics 25 but I have more than 10 variables.= 1 outcome variable and 11 predictors/factors. The big number of factor variables can be explained by the fact ...
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32 views
Log-linear regression: interpretation of RSE
AIM: To really, really understand what the model outputs mean in a log-linear regression, specifically, how to interpret the residual standard error (RSE).
I have read this post but it does not ...
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1answer
242 views
Confidence interval of a log-linear regression
AIM: Make a confidence interval statement on a log-linear regression
I have read posts like:
Interpreting Standard Deviation of Natural Log Transformed Data
Lognormal Regression?
But they do not ...
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16 views
INTERPRET A REGRESSION MODEL WHEN OUTCOME VARIABLE IS LOG TRANSFORMED [duplicate]
I have used a linear model between a log-transformed outcome variable and a group of predictor variables. In this model, the dependent variable is in its log-transformed state, and the independent ...
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11 views
Log-linear BIAS adjustment
I have a loglinear model of:
$log(\mu(S_{ij|gij}))=\alpha_0+\alpha_1g_{ij}$
where gij is distance, and Sij is connectivity
There is a bias in the distribution of count values for the outcome ...
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58 views
Poisson log linear Regression: using either R or python
I was hoping someone can help me with this problem. I posted a similar question earlier but it's not the same.
I have the following:
A 2x2 matrix of structural connectivity values between brain ...
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2answers
114 views
Interpretation of β in case of log-lin model for relationship between X and Y
In many papers, the dependent variable is transformed by taking natural log. For instance, consider the following model:
$$\newcommand{\Cov}{{\rm Cov}}
\ln(\text{Y}) = \alpha + \beta\, X_1 + \epsilon
...
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32 views
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28 views
Logistic regression and log-inear
I do not know why log-linear is non-sensitive margins and logistic regression is sensitive margins. Both are using odds ratios Can anyone give some explanation.
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483 views
Predicting probabilities after log-linear regression
I would like to estimate a log-linear regression and examine the results with Stata's marginsplot command. I have transformed my dependent variable into natural logarithm (to make a highly skewed ...
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1answer
347 views
Check log-linearity of a continuous variable to predict survival
I have the following survival data: cases with a continuous variable risk_factor wich higher values having a higher HR (1.026, CI: [1.017-1.034], p = 2.03e-09) for ...
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23 views
What is the appropriate analysis for this type of repeated measures multi-binary data?
There is a popular theory within psychology that certain emotions will trigger "prototypical" facial expressions defined by the simultaneous contraction of specific facial muscles. For example, if a ...
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1answer
142 views
Log-linear regression preferred over logistic regression for categorical vars?
I read here that, when all variables are categorical, log-linear is preferred over logistic regression "because log-linear is merely an extension of the chi-square test." I don't have a stats ...
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31 views
Conceptual question about log-linear analysis
I have measured the binary occurrence of three types of events on multiple days. Theory suggests that these events are not independent and should occur on the same days more than would be expected ...
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117 views
Difference between PROC CATMOD and PROC GENMOD for log-linear regression
I am reading "An Introduction to Categorical Data Analysis, Second Edition" by Alan Agresti. Data I am trying to fit is presented in Table 7.3 in the book. The log-linear regression by PROC GENMOD is ...
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1answer
78 views
How do I interpret the coefficients of a log-linear regression with quadratic terms?
I have a regression equation of this kind:
$$\log {y} = a + bx + cx^2 + \epsilon$$
where $a$ is the intercept, $b$ and $c$ are the coefficients of $x$ and $x^2,$ and $\epsilon$ is the error. How do ...
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81 views
Log-linear analysis versus independent chi-squares result
I am analyzing a number of categorical variables, and used log-linear modeling in SPSS to see whether there is association between any of them. I have some variables, however, which turn out to be non-...
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2answers
450 views
How can I interpret intercept when my dependent variable is in log form?
My model consists of both log independent and dependent variables, and percentage share, as well as number of people and etc. My dependent variable is log(GPD per capita in USD), my statistic package ...
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1answer
47 views
Newton-Raphson Error
According to Agresti(2013) pg 364-365, iterative methods such as Newton-Raphson methods, $
\begin{aligned}
\beta^\text{new} &= \beta^\text{old} + (X^{T}WX)^{-1}X^{T}(V)
\end{aligned}
$ help to ...
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198 views
Log-normal vs. log-linear vs. logging the response variable
I've been reading a lot of Wikipedia pages and StackExchange/CrossValidated posts, and I have come to a point where I realize I do not understand some of the terminology I have been using.
What's ...
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1answer
210 views
How are graphical models “a subset of log-linear models”?
Caveat lector: I am not sure what is meant by a "log-linear model". The Wikipedia page makes it seem as if log-linear model is an alternative term for exponential family.
This description of a book ...
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1answer
79 views
Log-linear model vs Multinomial-Dirichlet model for contingency table
Given a 1x3 contingency table of the form
$$[y_1,y_2,y_3]$$
where each $y_i$ represents a count on some random variable $$X\sim Multinomial(n, \pi_1,\pi_2,\pi_3)$$
We can estimate the vector of ...
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2answers
899 views
Poisson regression vs log-linear model
I'm confused about the difference between log-linear model and poisson regression and I am not sure which one to use to answer my research question.
In the experiment, participants were grouped into ...
2
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1answer
133 views
What does it mean if the residuals for a log-linear model are all zero?
Probably a very basic question, but I have a contingency table formed of 3 categorical variables (one with 3 levels, the rest with 2) and have been asked to try to test the association between them ...
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102 views
How is a covariate added to a log-linear model?
There are a number of good Q/As about log-linear models (i.e., here). The data I am analyzing is off shifts between categories, 0, ...
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148 views
Bootstrapping in contingency table
I have categorical data represented by a two-way contingency table (say $Y_{1}$ and $Y_{2}$, each with three levels). The data consists of fully observed counts (where data on both $Y_{1}$ and $Y_{2}$...
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38 views
Present difference in estimates for positively-skewed continuous outcomes
I'm working with a dataset containing results from two types of cognitive tests:
Pairs-matching test (say, $Y_1$), which recorded as number of incorrect matches (discrete count of mistakes, ranging ...
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0answers
842 views
semi-log (log linear) regression model
I know there are different reasons for choosing a particular model (e.g. log log, semi log, lin log).
I read somewhere that the semi log (where only the log of Y is taken) corresponds to a ...
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1answer
45 views
Is there a multiple regression model with both percentage and unit changes in $Y$?
In a standard linear model, $Y = \beta_0 + \beta_1 X_1 + \beta_2 X_2$, a unit increase in $X_1$ leads to a $\beta_1$ increase in $Y$ (likewise for $X_2$).
In a log-level model, $\ln(Y) = \beta_0 + \...
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55 views
Distinguish 2-way and 3-way interactions in binary data, independent of reference category
$\newcommand{\P}{\mathbb{P}}$I have three variables $X_a, X_b, X_c \in \{0, 1\}$ and I define a joint distribution:
$$
\P(X_a, X_b, X_c) \propto \exp
\left \{
\theta_{abc} \mathbb{I}_{\{X_a = 0 \...
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1answer
123 views
Effect Size log linear model when predictor is in percent
When performing a linear regression with a log-transformed dependent variable, one has to exponentiate the estimated coefficient of a predictor, subtract it by one and multiply it by 100 in order to ...
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1answer
753 views
Log-linear regression vs. Poission regression
In this post, OP asked the difference between log linear regression and logistic regression. Two answers in the post are very clear and directly address OP's question.
I understand Log-linear ...
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0answers
135 views
On the (wrong?) interpretation of log-linear models
For simplicity, let $X$ be a continuous random variable and assume that
${E}[\ln(Y)|X] = \beta X$, i.e., the conditional expectation of $Y$ given $X$ is proportional to $X$.
According to many ...
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1answer
161 views
What distribution to fit if the log of log is still convex?
I am trying to fit a model with variable x, and y. plot(x, y) shows that it is convex (downward) and decaying which makes me think I need to make a log ...
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168 views
Log-linear analysis of transition matrices using R
I have some demographic transition matrices that I want to compare using a log linear analysis, but am having some trouble with model construction in R. I have read through several tutorials on log-...
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2answers
300 views
Check for endogeneity
I run a log linear model, as $log(y) = b_0 + b_1x_1 + b_2x_2 + e$. I think $x_1$ may be endogenous and I would like to test it, so that I can consequently run a two-stage model. I would like to know ...
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0answers
179 views
Analysing categorical variables across several categories (LogLinear analysis?)
I'm editing this question in hopes of improving it, and thus receiving some advice on it.
I have collected info on diet from several populations. There are different groups (e.g. ElMolo) made of ...
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0answers
254 views
Nonlinear regression for a log-linear model
I have data points $(x_i, y_i), i = 1, \dots, N$, and a model (log-linear) with parameters $w_j, j = 0, \dots, m$ such that $y_i=\alpha_i e^{w_0+w_1x_i+w_2x_i^2+\dots+w_mx_i^m}+ n_i$, where $n_i$ are ...
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0answers
36 views
Bacteria counts in petri dish confusion
I'm currently (attempting) to help a fellow student with some statistical analysis. Basically she is looking at the effect of a sugar treatment on bacterial growth within a petri dish.
She has three ...
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1answer
301 views
What's the difference in growth of Y in a linear regression model when using a log-lin model or a lin-log model
Description
I'm currently studying a chapter on linear regression analysis. I have come to a section where we study the interpretation of the coefficients with logarithmically transformed variables. ...
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1answer
47 views
I want to find contributions of each independent variables
I would like to get contributions of independent variables (factors driving sales) in absolute dollar values.
The log linear equation looks like this:
$$\ln(\text{sales})=b_1 \times \ln(\text{...
2
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1answer
116 views
Multivariate Log-linear Model
I know from here that a log-linear model can be used to estimate a conditional probability of class $c$ given the feature representation $d$ of datapoint $x$.
$p(c|d;\theta) = \frac{exp(\theta.d_c)}{\...
