Hi, Franco, I can understand your confusion! This block is very unusual. In all fairness, that bock does what it says it will do, but it is unclear what it’s intended purpose is. I think it really computes "a+(b*)" and "-i(a-(b*))".
It does not appear to be used by any other blocks in the CASPER library. I think this block should be removed from the library (or modified to match the expectations from its name) unless anyone can justify its continued existence in its current state. Hope this helps, Dave > On Oct 3, 2016, at 10:44, Franco <francocuro...@gmail.com> wrote: > > Hi > > Well I feel a little bit stupid asking this, but from the addsub block: > > > Adds and subtracts the complex inputs. > If a = w + ix, b = y + iz then > a+b = (w+y)/2 + i(x-z)/2 and > a-b = (x+z)/2 + i(y-w)/2 > > Why it does it like this? Shouldn't it be simply: > > a+b = w+y + i(x+z) > > a-b = w-y + i(x-z) > > I could understand the division by two as a way to avoid overflow, but not > the rest of the changes. > > Franco >
