# b: Box Product of Basis Functions In basefun: Infrastructure for Computing with Basis Functions

## Description

Box product of two basis functions

## Usage

 `1` ```b(..., sumconstr = FALSE) ```

## Arguments

 `...` named objects of class `basis` `sumconstr` a logical indicating if sum constraints shall be applied

## Details

`b()` joins the corresponding design matrices by the row-wise Kronecker (or box) product.

## Examples

 ``` 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22``` ``` ### set-up a Bernstein polynomial xv <- numeric_var("x", support = c(1, pi)) bb <- Bernstein_basis(xv, order = 3, ui = "increasing") ## and treatment contrasts for a factor at three levels fb <- as.basis(~ g, data = factor_var("g", levels = LETTERS[1:3])) ### join them: we get one intercept and two deviation _functions_ bfb <- b(bern = bb, f = fb) ### generate data + coefficients x <- expand.grid(mkgrid(bfb, n = 10)) cf <- c(1, 2, 2.5, 2.6) cf <- c(cf, cf + 1, cf + 2) ### evaluate bases model.matrix(bfb, data = x) ### plot functions plot(x\$x, predict(bfb, newdata = x, coef = cf), type = "p", pch = (1:3)[x\$g]) legend("bottomright", pch = 1:3, legend = colnames(model.matrix(fb, data = x))) ```

basefun documentation built on May 31, 2017, 2:27 a.m.