Just to be clear, this does: currentVector-otherVector ? currentVector.assign(otherVector, Functions.minus);
On Fri, Feb 19, 2010 at 2:57 AM, Jake Mannix <jake.man...@gmail.com> wrote: > to do subtractFrom, you can instead just do > > Vector.assign(otherVector, Functions.minus); > > The problem is that while DenseVector has an optimization here: if the > BinaryFunction passed in is additive (it's an instance of PlusMult), > sparse iteration over "otherVector" is executed, applying the binary > function and mutating self. AbstractVector should have this optimization > in general, as it would be useful in RandomAccessSparseVector (although > not terribly useful in SequentialAccessSparseVector, but still better than > current). > > -jake > > On Thu, Feb 18, 2010 at 1:19 PM, Robin Anil <robin.a...@gmail.com> wrote: > > > I just had to change it at one place(and the tests pass, which is scary). > > Canopy is really fast now :). Still could be pushed > > Now the bottleneck is minus > > > > maybe a subtractFrom on the lines of addTo? or a mutable negate function > > for > > vector, before adding to > > > > Robin > > > > > > > > On Fri, Feb 19, 2010 at 2:43 AM, Jake Mannix <jake.man...@gmail.com> > > wrote: > > > > > I use it (addTo) in decomposer, for exactly this performance issue. > > > Changing > > > plus into addTo requires care, because since plus() leaves arguments > > > immutable, > > > there may be code which *assumes* that this is the case, and doing > > addTo() > > > leaves side effects which might not be expected. This bit me hard on > svd > > > migration, because I had other assumptions about mutability in there. > > > > > > -jake > > > > > > On Thu, Feb 18, 2010 at 1:09 PM, Robin Anil <robin.a...@gmail.com> > > wrote: > > > > > > > ah! Its not being used anywhere :). Should we make that a big task > > before > > > > 0.3 ? Sweep through code(mainly clustering) and change all these > > things. > > > > > > > > Robin > > > > > > > > > > > > > > > > On Fri, Feb 19, 2010 at 2:36 AM, Sean Owen <sro...@gmail.com> wrote: > > > > > > > > > Isn't this basically what assign() is for? > > > > > > > > > > On Thu, Feb 18, 2010 at 9:04 PM, Robin Anil <robin.a...@gmail.com> > > > > wrote: > > > > > > Now the big perf bottle neck is immutability > > > > > > > > > > > > Say for plus its doing vector.clone() before doing anything else. > > > > > > There should be both immutable and mutable plus functions > > > > > > > > > > > > > > > > > > > > >
