Looks like Lippu's solution may not generalize: ]hermy=. (([: <: [: +: 0 ?@$~ ,~) j. [: <: [: +: 0 ?@$~ ,~) 3 _0.771524j0.930188 _0.801744j0.329038 _0.650518j_0.830576 0.892523j_0.58658 0.0113443j0.681753 0.552033j0.183426 _0.385276j0.260412 _0.475036j0.982381 0.0801071j_0.557168
ishermitian (+>/~@i.@#"_*|:@:+) hermy NB. From Lippu 0 ishermitian ((% 1 + =@i.@#)@:++@|:) hermy NB. From Raul 1 On Tue, Jan 15, 2013 at 1:31 PM, km <k...@math.uh.edu> wrote: > This is very neat, Raul. Thanks. > > Kip Murray > > Sent from my iPad > > > On Jan 15, 2013, at 7:12 AM, Raul Miller <rauldmil...@gmail.com> wrote: > > > It's easy because isHermitian is so close to what you need for hft. > > In other words, hft=: -:@+ |: almost works, but it should only reduce > > the diagonal by half, not the rest of it. hft=: (% 1 + =@i.@#)@:+ > > +@|: is more complicated but structurally similar. > > > > FYI, > > > > -- > > Raul > > > > On Tue, Jan 15, 2013 at 8:05 AM, Aai <agroeneveld...@gmail.com> wrote: > >> Why is it easy? From the point of view of a mathematician perhaps. I > just > >> experimented towards the desired result. > >> > >> ishermitian ((]+[*~:) +@|:) A > >> 1 > >> ishermitian (+ +@|: * >/~@i.@#) A > >> 1 > >> > >> > >> > >> On 15-01-13 11:25, km wrote: > >>> > >>> This is an easy one. A Hermitian matrix matches its conjugate > transpose. > >>> Write a verb hft that creates a Hermitian matrix from a triangular one > that > >>> has a real diagonal. > >>> > >>> ishermitian =: -: +@|: > >>> ]A =: 2 2 $ 1 2j3 0 4 > >>> 1 2j3 > >>> 0 4 > >>> ]B =: hft A > >>> 1 2j3 > >>> 2j_3 4 > >>> ishermitian A > >>> 0 > >>> ishermitian B > >>> 1 > >>> > >>> Kip Murray > >>> > >>> Sent from my iPad > >>> ---------------------------------------------------------------------- > >>> For information about J forums seehttp://www.jsoftware.com/forums.htm > >> > >> > >> -- > >> Met vriendelijke groet, > >> @@i = Arie Groeneveld > >> > >> > >> ---------------------------------------------------------------------- > >> For information about J forums see http://www.jsoftware.com/forums.htm > > ---------------------------------------------------------------------- > > For information about J forums see http://www.jsoftware.com/forums.htm > ---------------------------------------------------------------------- > For information about J forums see http://www.jsoftware.com/forums.htm > -- Devon McCormick, CFA ^me^ at acm. org is my preferred e-mail ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
