I just went into the casper_library directory and ran "git grep -l complex_addsub". I now realize that maybe the block is used by a block in a .slx format file which that command will not find. So maybe it is used. To be sure, one would have to use some form of the "find_system" command at the matlab prompt.
Dave > On Oct 3, 2016, at 16:10, Franco Curotto <francocuro...@gmail.com> wrote: > > Thanks! That's a relief, for a moment there I doubted my high school math > knowledge. Just out of curiosity, how do you check if a block is used by > another block in the library? > > Franco > > On 10/03/2016 06:14 PM, David MacMahon wrote: >> 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 >>> <mailto: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 >>> >> >