Hi, Has anyone in R core thought about providing "hyper-dual numbers" in R? Hyper-dual (HD) numbers, invented by Jeffrey Fike at Stanford, are useful for computing exact second-order derivatives (e.g., Hessian). HD numbers are extensions of complex numbers. They are like "quaternions" and have 4 parts to them (one real and 3 non-real). They seem to be available in Julia. Obviously, the HD numbers involve a lot more book keeping.
http://adl.stanford.edu/hyperdual/ Thanks, Ravi [[alternative HTML version deleted]] ______________________________________________ R-devel@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-devel
