  A fast algorithm for B-splines in mixed models is presented. B-splines have
local support and are computational attractive, because the corresponding
matrices are sparse. A key element of the new algorithm is that the local
character of B-splines is preserved, while in other existing methods this local
character is lost. The computation time for the fast algorithm is linear in the
number of B-splines, while computation time scales cubically for existing
transformations.
