mgcv (version 1.8-12)

smooth.construct.tensor.smooth.spec: Tensor product smoothing constructor

Description

A special smooth.construct method function for creating tensor product smooths from any combination of single penalty marginal smooths.

Usage

"smooth.construct"(object, data, knots)

Arguments

object

a smooth specification object of class tensor.smooth.spec, usually generated by a term like te(x,z) in a gam model formula

data

a list containing just the data (including any by variable) required by this term, with names corresponding to object$term (and object$by). The by variable is the last element.

knots

a list containing any knots supplied for basis setup --- in same order and with same names as data. Can be NULL. See details for further information.

Value

"tensor.smooth". See smooth.construct, for the elements that this object will contain.

Details

Tensor product smooths are smooths of several variables which allow the degree of smoothing to be different with respect to different variables. They are useful as smooth interaction terms, as they are invariant to linear rescaling of the covariates, which means, for example, that they are insensitive to the measurement units of the different covariates. They are also useful whenever isotropic smoothing is inappropriate. See te, smooth.construct and smooth.terms.

References

Wood, S.N. (2006) Low rank scale invariant tensor product smooths for generalized additive mixed models. Biometrics 62(4):1025-1036

See Also

cSplineDes

Examples

## see ?gam