block_design function

Transform a Spline Design Matrix in block compressed form

block_design(X, degree)

Arguments

• X: The design matrix, as given by splines2::bSpline.
• degree: Degree of the spline regression, as used in function splines2::bSpline.

Returns

A matrix B with all non-zero entries of X and a vector of indices alpha representing the positions of the non-zero blocks of X.