I should also note that the reason why any correctness error has not been seen in minus() is that it's basically not used - any time I want to use something like that, I first check whether a new copy is needed, or whether a mutating method can be allowed, and if it can, I just do:
mutatableOne.assign(otherVector, Functions.minus) which does in-place subtraction without creating a new vector. Similarly for plus, either of these work nicely: mutatableOne.assign(otherVector, Functions.plus) or the shorthand otherVector.addTo(mutableOne) -jake On Mon, Apr 19, 2010 at 9:52 AM, Sean Owen <sro...@gmail.com> wrote: > On Mon, Apr 19, 2010 at 5:33 PM, Jake Mannix <jake.man...@gmail.com> > wrote: > > result.times(-1.0) > > with > > result.assign(Functions.negate) > > Cool, good one. > > > The efficiency points are twofold: number of nonzero elements, and > > the impl: you don't want to iterate over a vector of any type while > > continually calling setQuick() on a SequentialAccessSparseVector - > > that is horribly inefficient, as it causes a binary search each time, > > followed by a possible copy/shift of most of the index and value > > arrays. > > ah yeah sure. So really it'd be easier to specialize the one where > random access is slow. I can manage that. >
