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1 vote
0 answers
141 views

how well would a robust mixed model fit these data? R (rlmer)

I want to investigate Y ~ X1 * X2 + (1|ID on this dataset (there's a plot of these data in that post too, it's the same dataframe) Y is a continuos outcome ...
Larissa Cury's user avatar
2 votes
1 answer
145 views

MARS vs. CART regression predictive power

I have been wondering recently about the prediction power of the two similar models: Decision Trees and the MARS model (instead of fitting the mean to the subsets, OLS line is estimated). Given that ...
Fatafim's user avatar
  • 205
1 vote
1 answer
86 views

Does the P value need to be "back- transformed" after logging one variable in Regression analyse?

I have a data series, sediment concentration in water Vs Time. The data is not normal but I want to use regression and so have logged the sediment concentration (log10(x)). The residual and fit to ...
Rose's user avatar
  • 11
2 votes
0 answers
26 views

Sample size planning method differs from analysis method

I have seen some articles using one method for sample size estimation(two sample comparison for means or proportions) and subsequently using regression analysis/non parametric methods. If I have a ...
user45765's user avatar
  • 1,445
6 votes
4 answers
3k views

Is there a non-parametric form of a 3-way ANOVA?

I am currently in the process of writing a publication about the home range of cat shark species in South Africa. However, I am currently struggling with how to create an interaction model of shark ...
Tom Johnson's user avatar
1 vote
0 answers
23 views

Design points of local polynomial regression

Let the random set $\{(Y_{t},X_t)\}_{t=1}^n$ follow the model: $$Y_t=m(X_t)+\epsilon_t,\quad t\in\{1,\cdots,n\}\quad (1)$$ where $\epsilon_t$ is a random error term and $m(\cdot)$ is an unknown smooth ...
Celine Harumi's user avatar
4 votes
2 answers
1k views

How to create a B-spline basis without intercept and linear trend included?

I want to fit the following model using splines: \begin{align} Y(t) = \beta_0 + \beta_1t + \sum_{j=2}^{d} \beta_jB(t)_j \end{align} where $B_j$ are the basis functions. However, when I run the ...
Dries De Witte's user avatar
2 votes
1 answer
737 views

Is Kernel-Regression parametric or non-parametric?

As the title says, is kernel regression a parametric or non-parametric method, and how can this be motivated/explained?
Alexander's user avatar
0 votes
1 answer
575 views

Closed form equations for simple linear regression estimators

I'm learning specifically about different forms of simple linear regression including ordinary least squares, median absolute deviation, and Theil-Sen. I have no background whatsoever in linear ...
hachiko's user avatar
  • 89
0 votes
2 answers
170 views

can daily count data use GAM ordered categorical family, proportional-odds model?

The observed response variable Y takes on one of K(=21) ordered categories. Here is a summary of my response data (count data: the number of hospital admission in each day), y has observations across ...
Thomas's user avatar
  • 37
5 votes
0 answers
131 views

How can I make a prediction interval for a future response (not its mean) in regression by using bootstrap?

I'd like to know how I can use bootstrap to predict the confidence interval for a future response (not for its mean) no matter what theorical model and error distribution are, I know I can train the ...
Davi Américo's user avatar
1 vote
1 answer
477 views

Difference between kernel linear regression and non-parametric regression

A quick perplexity popped up in my mind while reading about non-parametric linear regression. In linear regression, we model our response $\textbf{y} \sim \mathcal{N}(X\beta, \sigma^2I)$ so basically ...
James Arten's user avatar
1 vote
1 answer
365 views

What would be the interpretation of asymmetric kernels in Gaussian Process Regression?

This paper involves with asymmetric Kernels. They claim that this arises due to local parameters. But this is not really true. They induce a particular asymmetric structure in the Kernel yet still ...
safetyduck's user avatar
0 votes
0 answers
607 views

No significant interaction in OLS, but significant in pairwise comparison

I have two independent categorical variables — (i) A: {1, 2, 3}, (ii) B: {0, 1} — with a continuous outcome variable ...
Alex Zakharov's user avatar
0 votes
1 answer
57 views

Validity of multilevel modeling to include results for multiple psychometric tests with subscales #statsnube

I have survey data for approx n = 1650 for multiple psychometric tests (all participants have completed all the tests), and about 12 outcome variables (from a PCA of a 52-question survey, e.g. ...
scvbelle's user avatar

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