# TPSbits

## TPSbits

TPSbits creates structures to enable ASReml-R to fit the 2D tensor-product splines of Rodriguez-Alvarez et al (2018, Spatial Statistics 23, 52-71). It also enables extraction and plotting of the components of the splines, and includes the following functions:

`bbasis`

: creates B-spline bases.`tpsmmb`

: creates design matrices and vectors for 2d tp-splines to go into mbf or grp constructs.`edf`

: calculates EDF for random terms in a model (WARNING: requires scaled identity variance models).`tpsfitted`

: extracts components of fitted spline.`tpsurface`

: plots surfaces as contour or tile plots.`csteps`

: calculates nice intervals for contour plots.

The package can be installed in R from a local archive in the usual way, either after downloading the respective file or pasting in the URL. There are two example scripts to illustrate usage:

- TPSexamples.R: shows detailed examples of usage.
- TPSexamplesVsSpATS.R: shows usage to get same results as SpATS package.