schoenberg

The schoenberg package for R provides ggplot-based graphics and useful functions for GAMs fitted using the mgcv package.

I've abondonded this project, moving development to the gratia package because the name "schoenberg" has recently been taken by another package on CRAN. I'm leaving this repo up though as I know some people were using it in scripts, I was using it in a preprint of a GAM paper that is under review, and I have blog posts using it.

Build status

Features

The main features of schoenberg are currently

• A ggplot2-based replacement for mgcv:::plot.gam(): draw(gam_model).

  Note specialist smoothers (bs %in% c("re","fs","mrf","so")) are not supported, but univariate, factor and continuous by-variable smooths, and bivariate tensor product smooths are supported,

• Estimatation of derivatives of fitted smoothers: fderiv(gam_model),

• Estimation of point-wise across-the-function confidence intervals and simultaneous intervals for smooths: confint(gam_model).

Installing schoenberg

schoenberg is under active development and has not yet had its first release to CRAN. The easiest way to install the package is via the install_github() function from package devtools. Make sure you have devtools installed, then run

devtools::install_github("gavinsimpson/schoenberg")

to install the package.

History

schoenberg grew out of an earlier package, tsgam, which was originally intended to be used with GAMs fitted to time series. As I was developing tsgam however it became clear that the package could be used more generally and that the name "tsgam" was no longer appropriate. To avoid breaking blog posts I had written using tsgam I decided to copy the git repo and all the history to a new repo for the package under the name schoenberg.

Why schoenberg?

In naming his greta package, Nick Golding observed the recent phenomena of naming statistical modelling software, such as Stan or Edward, after individuals that played a prominent role in the development of the field. This lead Nick to name his Tensor Flow-based package greta after Grete Hermann.

In the same spirit, schoenberg is named in recognition of the contributions of Grace Wahba, who did pioneering work on the penalised spline models that are at the foundation of the way GAMs are estimated in mgcv. I wanted to name the package grace, to more explicitly recognise Grace's contributions, but unfortunately there was already a package named Grace on CRAN. So I looked elsewhere for inspiration.

Grace Wahba is the IJ Schoenberg-Hilldale Professor of Statistics at the University of Wisconsin-Madison, where she has worked since 1967. The chair is named after Isaac J Schoenberg, a former University Madison-Wisconsin Professor of Mathematics, who in a 1946 paper provided the first mathematical reference to "splines".

The name schoenberg links and recognises two pioneers in the field of splines.