Re: Matrices as operators

*To*: mathgroup at smc.vnet.net*Subject*: [mg123060] Re: Matrices as operators*From*: Ray Koopman <koopman at sfu.ca>*Date*: Tue, 22 Nov 2011 05:34:28 -0500 (EST)*Delivered-to*: l-mathgroup@mail-archive0.wolfram.com*References*: <jaal4e$12d$1@smc.vnet.net>

On Nov 20, 2:34 am, Chris Young <c... at comcast.net> wrote: > I'd like to be able to abbreviate matrices such as rotation matrices > so that I don't have to repeat the argument. This way I can pass in > more complicated arguments and it also shows the structure of the > transformation more clearly. > > Through[( { > {Cos, -Sin}, > {Sin, Cos} > } )[=CE=B8]] > > will get me partway there: > > Out: {{Cos, -Sin}[=CE=B8], {Sin, Cos}[=CE=B8]} > > I have to apply Thread and Through again to finally get what I want: > > In: Thread[Through[{{Cos, -Sin}[=CE=B8], {Sin, Cos}[=CE=B8]}]] > > Out: {{Cos[=CE=B8], (-Sin)[=CE=B8]}, {Sin[=CE=B8], Cos[=CE=B8]}} > > Is there a shortcut way to do this all in one step? > > Thanks very much for any help. > > Chris Young > c... at comcast.net If you're worried about redundant calculations when the matrices are bigger than 2 x 2 and the functions are more complicated than Sin and Cos, try something like R[t_] := {{#1,-#2},{#2,#1}}&[Cos@t,Sin@t]

**Follow-Ups**:**Re: Matrices as operators***From:*Oliver Ruebenkoenig <ruebenko@wolfram.com>