mfp2: Multivariable Fractional Polynomial Models with Extensions

Fits multivariable fractional polynomial models with selection of predictors and functional forms. The mfp2() function supports generalized linear models, including Gamma and inverse-Gaussian regression; negative-binomial, multinomial and ordinal regression; generalized estimating equations for clustered data; Cox and parametric survival models; and Fine-Gray competing-risks models. Extensions include approximate cumulative distribution transformations for sigmoid-shaped associations and spike-at-zero modelling for semi-continuous covariates. The mfpi() function assesses interactions between a categorical grouping variable and continuous, binary, or categorical predictors. Fractional polynomial modelling is described by Royston and Altman (1994) <doi:10.2307/2986270> and Royston and Sauerbrei (2008, ISBN:978-0-470-02842-1). The approximate cumulative distribution extension follows Royston (2014) <doi:10.1177/1536867X1401400206> and Royston and Sauerbrei (2016) <doi:10.1177/1536867X1601600109>. Spike-at-zero modelling follows Becher et al. (2012) <doi:10.1002/bimj.201100263>. Interaction analyses follow Royston and Sauerbrei (2004) <doi:10.1002/sim.1815>, Royston and Sauerbrei (2013) <doi:10.1002/sim.5813>, and Royston and Sauerbrei (2014) <doi:10.1002/sim.6308>.

Version: 1.1.0
Depends: R (≥ 4.2.0)
Imports: stats, survival, nnet, utils, Rcpp
LinkingTo: Rcpp
Suggests: knitr, testthat (≥ 3.2.0), rmarkdown, patchwork, fastglm (≥ 0.1.1), MASS, numDeriv, rms (≥ 7.0-0), ggplot2 (≥ 3.4.0), geepack (≥ 1.3.0)
Published: 2026-11-02
DOI: 10.32614/CRAN.package.mfp2
Author: Edwin Kipruto [aut, cre], Michael Kammer [aut], Patrick Royston [aut], Willi Sauerbrei [aut]
Maintainer: Edwin Kipruto <kiprutoedwin2626 at gmail.com>
BugReports: https://github.com/EdwinKipruto/mfp2/issues
License: GPL-3
URL: https://github.com/EdwinKipruto/mfp2
NeedsCompilation: yes
Citation: mfp2 citation info
Materials: README, NEWS
CRAN checks: mfp2 results

Documentation:

Reference manual: mfp2.html , mfp2.pdf
Vignettes: ACD Transformations with mfp2 (source, R code)
Multivariable Fractional Polynomial Interaction Models (source, R code)
MFP Methodology and Practical Considerations (source, R code)
Modelling Spike-at-Zero Covariates with Fractional Polynomials (source, R code)

Downloads:

Package source: mfp2_1.1.0.tar.gz
Windows binaries: r-devel: mfp2_1.0.1.zip, r-release: mfp2_1.0.1.zip, r-oldrel: mfp2_1.0.1.zip
macOS binaries: r-release (arm64): mfp2_1.0.1.tgz, r-oldrel (arm64): mfp2_1.0.1.tgz, r-release (x86_64): mfp2_1.0.1.tgz, r-oldrel (x86_64): mfp2_1.1.0.tgz
Old sources: mfp2 archive

Reverse dependencies:

Reverse imports: ctlr, midoc, test2norm

Linking:

Please use the canonical form https://CRAN.R-project.org/package=mfp2 to link to this page.