All Questions
Tagged with model-selection multiple-regression
91
questions
0
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34
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The function step.lmRob() is not working [closed]
I have a linear model, which i analyzed (in R) through: lmrob_object<-lmrob(diff_mg ~ age + bmi + energy + fiber + ca + phos + iron + potas + supp + uni, data = data), where:
diff_mg is the DV (...
- 151
3
votes
2
answers
144
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Variable selection in logistic regression [duplicate]
So I'm trying to make a multivariate logistic regression model in R studio. I'm not sure how to go about this. What seemed to make sense to me was to model every predictor against the response ...
- 127
2
votes
1
answer
107
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R-squared vs adjusted R-squared in Hierarchical multiple regression
In hierarchical multiple regression (not to be confused with hierarchical linear models that account for variance components), you add model terms by block. The fit of the new model is measured by the ...
- 21
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19
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Was approaching this as a classification problem a mistake and should I have to use regression instead?
So I am training a model to predict baseball plate appearance outcomes, which I have been modelling as a single multi-class output problem, namely because single, mutually exclusive outcomes is what ...
1
vote
1
answer
77
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Why the significance of linear regression is different from anova
I am doing model selection and really confused about why the significance of the coefficient is different from ANOVA, which the coefficient is significant using the summary function, but when I put it ...
- 11
4
votes
1
answer
233
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A reasonable number of covariates after variable selection in a regression model
I read an unpublished paper. There is a regression model with about 20 covariates. The authors use a stepwise variable selection method and come to a model with two covariates with small p-values.
The ...
- 1,035
1
vote
1
answer
37
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Why this regression model with one predictor don't work?
I have this R script. I want to estimate the coefficient of the dependent variable Y based on several regression.
...
- 13
3
votes
1
answer
88
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compare model fit logistic regression negative two times log likelihood
I'm trying to decide between two logistic regression models. I think I've used the negative two times log likelihood criterion before. My two models are not nested - can I still use that approach? ...
- 53
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50
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bootstrapped l2,1 least square does not produce sparse solution
I am trying to model an autoregressive model with $\ell$-2,1 regularization, where $\|X\|_{2,1}=\sum_i|\sum_jX_{ij}|$:
$$y_{t+1} = wx_{t} + \lambda_1\|w\|_{2,1}, y\in \mathbb{R}^{n_1}, x\in \mathbb{R}^...
- 308
1
vote
0
answers
36
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Multiple regressions
Consider that we have two independent datasets $(Y_1, X_1)^\top, \dots, (Y_{n_1}, X_{n_1})^\top$, and the second denoted as $(Y`_1, X`_1)^\top, \dots, (Y`_{n_2}, X`_{n_2})^\top$. We assume that the ...
- 419
1
vote
2
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231
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Model Selection with AIC. Choosing between negative and positive AIC values
I have gone through the model selection process for my linear model prior and post model transformation. I would like to know whether it is ok for me to compare the AIC values for both models given ...
- 11
0
votes
1
answer
110
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Multiple linear regression model selection. Individually, X's and Y not correlated, but X's are significant predictors of Y in multiple regression?
My study is largely exploratory and looks at how environmental factors such as (physical characteristics, water quality and pesticide type and concentration) affect relative antioxidant enzyme mRNA ...
- 1
0
votes
1
answer
459
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Selecting the best regression model using R2 and AIC - what is the best approach?
I have a dataset in which I have one dependent and 3 independent variables (y ~ x1 + x2 + x3). For exploratory analysis, I have fitted the following models (using R):
...
- 23
1
vote
1
answer
350
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Does the column ordering matter in the stepwise algorithms used by R?
Suppose I have a large data set with variables $x_1, x_2, \ldots, x_p$ to predict response $y$ where $p$ is very large (however $n >> p$).
I would like to perform forward stepwise regression on ...
- 215
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29
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Selection of a “best” regression model using differet approaches
I need help with the following question.
I am really lost, so any help/hint would be much appreciated!
I am aware that for best fit model, we are looking for higher $R^2_{Adj}$, smaller $MS_{res}$, ...
- 133