splines2 0.5.1

Minor changes

• Fix broken @docType package documentation.

splines2 0.5.0

New features

• Added a new function named nsk() for natural cubic spline basis functions following the function survival::nsk() (introduced in survival package version 3.2-8).
• Added plot() methods to quickly visualize the spline basis functions.
• Added $ method to extract an attribute of the returned splines2 object.
• Added a new argument named periodic to bSpline() for periodic B-splines and a new class named PeriodicBSpline to the Rcpp interface: issue 19.
• Added a new argument named coef to the predict() methods to compute the responding spline function and made it possible to obtain the derivatives or update spline basis functions by passing ... to the update() methods.
• Added a new argument named trim to naturalSpline() to set the default boundary knots after trimming a fraction of observations.
• Added a new argument named warn.outside and a package option named splines2.warn.outside to specify if a warning should be thrown out for B-splines, etc. when any x is placed outside the boundary.
• Added the following function aliases to encourage the use in a model formula:
  • bsp() = bSpline()
  • msp() = mSpline()
  • isp() = iSpline()
  • csp() = cSpline()
  • nsp() = naturalSpline()
  • bpoly() = bernsteinPoly()
• Added a matrix named H to the attribution of objects for natural cubic splines so that users may transform cubic B-splines (from other software/packages) to the natural cubic splines (returned by naturalSpline()/nsp() or nsk()).

Major changes

• Adjusted the class order of the returned objects.
• Adjusted the default placement of the internal knots from the specified df to be equidistant if the internal knots resulting from quantiles are problematic. A warning will be thrown out in that case.

splines2 0.4.8

Bug fixes

• Fixed the Rcpp interface of PeriodicMSpline so that a simple knot sequence can be specified through set_knot_sequence: issue 18.

splines2 0.4.7

Minor changes

• Adjusted the column arrangement of the natural cubic spline basis matrix so that it matches the equations given in the JDS paper: issue 17.

splines2 0.4.6

New features

• Added update() methods to produce new spline basis functions based on the given object with specified updates in terms of degree and knots, etc.

Minor changes

• Appended a new class named splines2 to the output matrices to simplify some common S3 methods.

splines2 0.4.5

Minor changes

• Improved the computational efficiency of finding the knot intervals for x (by replacing the naive binary search implementation with std::upper_bound and std::distance).

splines2 0.4.4

New features

• Added the makepredictcall() methods for all available spline basis functions to help model.frame.default() create the right matrices when predicting from models with terms such as bSpline(), etc. Thanks Zheyuan Li for suggesting this feature.
• Added arguments derivs and integal to bSpline() for consistency with mSpline() and bernsteinPoly(), etc.

Minor changes

• Made the internal checking procedure more strict to throw an error if any internal knots are placed at or outside boundary: issue 5.

Bug fixes

• Fixed the predict() method for cSpline objects when scale = FALSE.

splines2 0.4.3

New features

• Enabled extended knot sequence that allows multiplicity of internal knots for B-splines, M-splines, I-splines, and C-splines in the C++ interface.
• Added type conversion to BernsteinPoly and PeriodicMSpline objects to the C++ interface.

Minor changes

• Added testing examples for constructing spline basis functions via the C++ interface.

splines2 0.4.2

New features

• Added knots() methods to extract internal knots and boundary knots from a given splines2 object.

Major changes

• Updated the generation of the knot sequence for periodic M-splines following Piegl and Tiller (1997), which relaxed the previous requirement that length(knots) >= degree to length(knots) >= degree - 1.

splines2 0.4.1

New features

• Added function naturalSpline() providing implementation of nonnegative natural cubic splines.
• Added argument periodic to function mSpline() for periodic M-splines.
• Added argument integral to function mSpline() for integrals of M-splines or periodic M-splines.
• Added deriv(), predict(), and print() method for naturalSpline class object.

Minor changes

• Updated the deriv() method for mSpline class object for periodic M-splines.

splines2 0.3.1

Minor changes

• Modified testing examples for CRAN tests on r-patched-solaris-x86 and r-oldrel-macos-x86_64.

splines2 0.3.0

New features

• Added function bernsteinPoly() providing implementation of generalized Bernstein polynomials.
• Added C++ interface that can be easily integrated with Rcpp.

Major changes

• Changed most implementations from R to C++ with help of Rcpp and RcppArmadillo to boost the performance.

Minor changes

• Made piece-wise constant basis functions continuous at right boundary knot for consistency with spline basis matrix of non-zero degrees.
• Changed the default value of argument intercept in function iSpline() and cSpline() to TRUE for a complete set of spline basis functions in shape-restricted regression.
• Removed the corresponding M-spline basis from attributes of outputs from iSpline() and cSpline().
• Removed the corresponding B-spline basis from attributes of outputs from bSpline().

Bug fixes

• Fixed deriv.mSpline() method for third derivatives of scaled C-splines.

splines2 0.2.8

Bug fixes

• Fixed inconsistency of argument df for piecewise constant basis functions when knots = NULL.

Minor changes

• Rewrote testing suite for using the tinytest package instead of testthat.

splines2 0.2.7

Minor changes

• Updated tests for R development version.

splines2 0.2.6

Minor changes

• Added checks for any internal knot incorrectly placed outside of the boundary knots and added warnings for users’ reference.

splines2 0.2.5

Minor changes

• Added more tests and increased code coverage.

Bug fixes

• Fixed evaluation of derivatives of M-splines for a single value. Thanks Ina Jazic for reporting the bug and providing possible fix.
• Fixed deriv.cSpline() method for derivatives of order greater than two when scale = TRUE.

splines2 0.2.4

New features

• Added function dbs() generating derivative of given order of B-splines. It is a similar function with splines::splineDesign(). However, it provides a more user-friendly interface and more consistent handling on NA’s.
• Added deriv() methods for derivatives of given order of any existing splines2 object that can be generated currently.

Major changes

• Added argument derivs to function mSpline() and iSpline() for derivatives.
• Changed all the classes of object generated for a better dispatching on methods.

Minor changes

• Added tests for all major functions with the help of package testthat.

Bug fixes

• Fixed the generation of splines without any internal knot.

splines2 0.2.3

Bug fixes

• Fixed one-piece constant basis for M-splines.

splines2 0.2.2

Bug fixes

• Fixed the NA’s handling in all the functions constructing spline basis matrix.

splines2 0.2.1

New features

• Added function bSpline() generating B-spline basis allowing zero degree or piecewise constant basis based on function bs() in the splines package.
• Introduced function bSpline() to allow M-splines of degree zero.
• Added function cSpline() constructing convex spline (C-spline) basis.
• Added predict() methods for bSpline2 object and cSpline object generated by bSpline() and cSpline(), respectively.
• Added print() methods for all splines2 objects developed so far.

Major changes

• Improved the function iSpline() to construct I-spline basis directly from B-spline basis instead of M-spline basis.

Minor changes

• Updated all CRAN URL to a canonical form suggested.

splines2 0.1.0

New features

• The first version of splines2 providing functions constructing M-spline, I-spline, and integral of B-spline basis.