Multivariable Fractional Polynomials

Fractional polynomials are used to represent curvature in regression models. A key reference is Royston and Altman, 1994.


31.08.2015 1.5.2 Minor corrections (Vignette float options error; function namespace). 04.02.2015 1.5.1 Minor corrections (Vignette keywords updated). 15.09.2014 1.5.0 New maintainer; 'vignettes' directory added. 28.11.2010 1.4.9 Minor corrections in fp.rescale. 19.09.2010 1.4.8 Call of final fitted glm/coxph model corrected (parent frame was missing). 01.06.2010 1.4.8 plot.mfp (temporarily) removed. 10.05.2010 1.4.8 Correction of rescaling procedure of log trafos in fp.rescale. 01.07.2009 1.4.7 summary.mfp added to avoid problems calling summary directly on mfp object.
29.08.2008 1.4.6 Minor corrections.
21.06.2008 1.4.5 Minor corrections of component 'fit'.
05.04.2008 1.4.4 predict.mfp added.
12.12.2007 1.4.3 Corrected in object$fit: Use quadratic in ln(X) when powers=(0,0).
11.11.2007 1.4.2 Minor corrections to use 'subset' properly and to allow to ignore 'data'. 01.03.2007 1.4.0 Data set 'GBSG' from the JRSS-A paper replaced by its Stata version. 'rescale' argument added to function call. 'keep' argument added to function call. Verbose output now shows also transformation functions of covariates. 21.12.2005 1.3.2 Scaling of variables is added to model fit used for output component 'fit'. 21.09.2005 1.3.1 Output corrected for FP2 with equal powers mfp now works even without any FP call New argument 'method' to select method for tie handling in Cox models Vignette updated. 01.05.2005 1.3.0 Changes in the primary ordering of variables Scaling changed Likelihood ratio tests are now used for all selections Plot of functional form corrected Print function corrected Value of mfp fit has new component fit' 04.08.2004 1.2.2 plot.mfp changed: new argumentvar'. New dataset `bodyfat' to be used as an example for linear regression. Vignette included. 31.07.2004 1.2.1 Original port

Reference manual

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1.5.2 by Stephan Luecke, 5 years ago

Browse source code at

Authors: original by Gareth Ambler <[email protected]> , modified by Axel Benner <[email protected]>

Documentation:   PDF Manual  

Task views: Survival Analysis

GPL (>= 2) license

Depends on survival

Imported by shrink, test2norm.

Suggested by bfp.

See at CRAN