Questions tagged [splines]
Splines are flexible functions, knit together from polynomial parts, used for approximation or smoothing. This tag is for any kind of spline (eg, B-splines, regression splines, thin-plate splines, etc).
674 questions
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chi-squared significant for dose-response function obtained through meta-analysis but confidence interval around plotted predicted values not
The question:
I obtained a dose-response function (predictor vs relative risk) through meta-analysis using the dosresmeta package for R. The package applies a random effects model (REML)and I fitted a ...
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Longitudinal intervention vs control with nonlinear rise–decay: phase-aware natural cubic spline mixed model?
Design:
18 participants total (12 intervention, 6 control).
Intervention group consumes a nutritional supplement once daily for 5 consecutive days; control group abstains throughout.
Outcomes are ...
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Time dependent coefficients for cox-ph model, how to model it?
I am modeling a CNS cancer survival data and my cox-ph model violates the PH assumption on most of the variables. Therefore I decided to model the time dependent coefficients accordingly, I thought ...
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3-part linear spline middle segment fitting in wrong direction?
I'm fitting a 3-part linear spline using the lspline package to model a time series with two known disruption periods. The knots are fixed at the disruption periods ...
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F statistic for spline terms in generalized additive model
I am performing a regression analysis using a generalized additive model, 2 spline terms and 12 linear terms. When I use the summary(gam_model) command, I get some F statistics for my 2 spline terms. ...
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Multivariable linear regression model with continuous predictors with a spike at 0
I want to build a prediction model of a continuous outcome Y. I have ~50 predictors that are count variables (number of hospitalizations by cause, number of drugs dispensed by type of drug). I was ...
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Interpreting hurdle model output with splines
I am trying to determine which variables affect the likelihood of lumpfish eating salmon lice and which variables predict the number of lice eaten. My data are highly zero-inflated, so I decided to ...
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Multiple imputation and modelling using penalised splines [closed]
I ran multiple imputation in R using mice. Only one categorical variable had missingness and I specified the imputation model to imputate it using ...
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Automatic fitting of constrained linear splines with fixed knots and slope sign constraints
I need to fit multiple constrained 3-part linear splines to nighttime lights time series data to model responses to disruptions (knots) with known start/end dates. Each spline has three segments:
fa: ...
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Robust sandwich estimator for a misspecified penalized Cox model
Using R survival package, I built a Cox model (discussed here) with pspline() terms. This is a large model with about 900,000 ...
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Contrasts for splines in Coxph
I have to get splines for age with reference at 55. How does one go about this? I found the following code but this does not calculate the contrasts between each value of age vs age=55. Shouldn't ...
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Python equivalent to an R GLM with ns() / bs() terms [closed]
I'm looking to port an R (generalized) linear model containing regression spline terms to Python. As a concrete example, let's say I have
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Comparing/scoring/ranking many candidate features fit using splines
I have about 100 biomarkers (serum protein concentrations; continuous) from about 200 subjects that could correlate with prognosis (binary, prevalence around 30%). The data are complete in that all ...
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How to estimate a spline trend when using yearmonth time variable (tsibble) [closed]
Im working my way through Rob Hyndman's book. He estimates a spline model where time is in years. I can find no examples where time is in yearmonths or yearquarters. I tried to estimate the below ...
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Interpretation of restricted cubic spline coefficients significance
Suppose we have a linear regression model fitted with rms::ols in R.
Now suppose we have our response (i.e., dependent) variable, which is ...
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