bspline {bspline} R Documentation

## bspline: build and use B-splines for interpolation and regression.

### Description

Build and use B-splines for interpolation and regression. In case of regression, equality constraints as well as monotonicity requirement can be imposed. Moreover, knot positions (not only spline coefficients) can be part of optimized parameters too. User is provided with functions calculating spline values at arbitrary points. This functions can be differentiated to obtain B-splines calculating derivatives at any point. B-splines of this package can simultaneously operate on a series of curves sharing the same set of knots. 'bspline' is written with concern about computing performance that's why the basis calculation is implemented in C++. The rest is implemented in R but without notable impact on computing speed.

### bspline functions

• bsc: basis matrix (implemented in C++)

• bsp: values of B-spline from its coefficients

• dbsp: derivative of B-spline

• par2bsp: build B-spline function from parameters

• bsppar: retrieve B-spline parameters from its function

• smbsp: build smoothing B-spline

• fitsmbsp: build smoothing B-spline with optimized knot positions

• diffn: finite differences

[Package bspline version 2.1 Index]